commitdbf1f13b3a6e9ee0c3c2ee77238b0d7783601479parent1bfe2f94456c9d9f816b11019a7b200aabb800f6Author:Virgil Dupras <hsoft@hardcoded.net>Date:Mon, 28 Nov 2022 16:22:54 -0500 ar/puff: replace ar/ungz See https://lists.sr.ht/~vdupras/duskos-discuss/%3C69cfdb97-49d6-dccd-c7bb-df3b40eab7e6%2540gmx.de%3EDiffstat:

A | fs/ar/puff.c | | | 736 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |

A | fs/ar/puff.fs | | | 2 | ++ |

D | fs/ar/ungz.c | | | 933 | ------------------------------------------------------------------------------- |

D | fs/ar/ungz.fs | | | 4 | ---- |

M | fs/tests/ar/all.fs | | | 2 | +- |

A | fs/tests/ar/puff.fs | | | 5 | +++++ |

D | fs/tests/ar/ungz.fs | | | 10 | ---------- |

A | license/madler-puff.txt | | | 20 | ++++++++++++++++++++ |

D | license/oriansj-ungz.txt | | | 37 | ------------------------------------- |

9 files changed, 764 insertions(+), 985 deletions(-)diff --git a/fs/ar/puff.c b/fs/ar/puff.c@@ -0,0 +1,736 @@ +/* Source: https://github.com/madler/zlib + * License: /license/madler-puff.txt + * + * puff.c is a simple inflate written to be an unambiguous way to specify the + * deflate format. It is not written for speed but rather simplicity. As a + * side benefit, this code might actually be useful when small code is more + * important than speed, such as bootstrap applications. For typical deflate + * data, zlib's inflate() is about four times as fast as puff(). zlib's + * inflate compiles to around 20K on my machine, whereas puff.c compiles to + * around 4K on my machine (a PowerPC using GNU cc). If the faster decode() + * function here is used, then puff() is only twice as slow as zlib's + * inflate(). + * + * All dynamically allocated memory comes from the stack. The stack required + * is less than 2K bytes. This code is compatible with 16-bit int's and + * assumes that long's are at least 32 bits. puff.c uses the short data type, + * assumed to be 16 bits, for arrays in order to conserve memory. The code + * works whether integers are stored big endian or little endian. + * + * In the comments below are "Format notes" that describe the inflate process + * and document some of the less obvious aspects of the format. This source + * code is meant to supplement RFC 1951, which formally describes the deflate + * format: + * + * http://www.zlib.org/rfc-deflate.html + */ + +/* + * Maximums for allocations and loops. It is not useful to change these -- + * they are fixed by the deflate format. + */ +/* maximum bits in a code */ +#define MAXBITS 15 +/* TODO: allow constant expressions array typedefs, for example MAXBITS+1 */ +#define MAXBITSPLUSONE 16 +/* maximum number of literal/length codes */ +#define MAXLCODES 286 +/* maximum number of distance codes */ +#define MAXDCODES 30 +/* maximum codes lengths to read */ + +// TODO: same here +//#define MAXCODES (MAXLCODES+MAXDCODES) + +#define MAXCODES 316 +/* number of fixed literal/length codes */ +#define FIXLCODES 288 +// TODO: can't #define right after a // comment + +/* input and output state */ +struct state { + /* output state */ + unsigned char *out; /* output buffer */ + unsigned int outlen; /* available space at out */ + unsigned int outcnt; /* bytes written to out so far */ + + /* input state */ + unsigned char *in; /* input buffer */ + unsigned int inlen; /* available input at in */ + unsigned int incnt; /* bytes read so far */ + int bitbuf; /* bit buffer */ + int bitcnt; /* number of bits in bit buffer */ +}; + +/* + * Return need bits from the input stream. This always leaves less than + * eight bits in the buffer. bits() works properly for need == 0. + * + * Format notes: + * + * - Bits are stored in bytes from the least significant bit to the most + * significant bit. Therefore bits are dropped from the bottom of the bit + * buffer, using shift right, and new bytes are appended to the top of the + * bit buffer, using shift left. + */ +static int bits(state *s, int need) +{ + int val; /* bit accumulator (can use up to 20 bits) */ + + /* load at least need bits into val */ + val = s->bitbuf; + while (s->bitcnt < need) { + if (s->incnt == s->inlen) { + fputs("out of input\n", ConsoleOut()); + abort(); + } + val |= (s->in[s->incnt++]) << s->bitcnt; /* load eight bits */ + s->bitcnt += 8; + } + + /* drop need bits and update buffer, always zero to seven bits left */ + s->bitbuf = (val >> need); + s->bitcnt -= need; + + /* return need bits, zeroing the bits above that */ + return (val & ((1 << need) - 1)); +} + +/* + * Process a stored block. + * + * Format notes: + * + * - After the two-bit stored block type (00), the stored block length and + * stored bytes are byte-aligned for fast copying. Therefore any leftover + * bits in the byte that has the last bit of the type, as many as seven, are + * discarded. The value of the discarded bits are not defined and should not + * be checked against any expectation. + * + * - The second inverted copy of the stored block length does not have to be + * checked, but it's probably a good idea to do so anyway. + * + * - A stored block can have zero length. This is sometimes used to byte-align + * subsets of the compressed data for random access or partial recovery. + */ +static int stored(state *s) +{ + unsigned int len; /* length of stored block */ + + /* discard leftover bits from current byte (assumes s->bitcnt < 8) */ + s->bitbuf = 0; + s->bitcnt = 0; + + /* get length and check against its one's complement */ + if (s->incnt + 4 > s->inlen) + return 2; /* not enough input */ + len = s->in[s->incnt++]; + len |= s->in[s->incnt++] << 8; + if (s->in[s->incnt++] != (~len & $ff) || + s->in[s->incnt++] != ((~len >> 8) & $ff)) + return -2; /* didn't match complement! */ + + /* copy len bytes from in to out */ + if (s->incnt + len > s->inlen) + return 2; /* not enough input */ + if (s->out != NULL) { + if (s->outcnt + len > s->outlen) + return 1; /* not enough output space */ + while (len--) + s->out[s->outcnt++] = s->in[s->incnt++]; + } + else { /* just scanning */ + s->outcnt += len; + s->incnt += len; + } + + /* done with a valid stored block */ + return 0; +} + +/* + * Huffman code decoding tables. count[1..MAXBITS] is the number of symbols of + * each length, which for a canonical code are stepped through in order. + * symbol[] are the symbol values in canonical order, where the number of + * entries is the sum of the counts in count[]. The decoding process can be + * seen in the function decode() below. + */ +struct huffman { + short *count; /* number of symbols of each length */ + short *symbol; /* canonically ordered symbols */ +}; + +/* + * Decode a code from the stream s using huffman table h. Return the symbol or + * a negative value if there is an error. If all of the lengths are zero, i.e. + * an empty code, or if the code is incomplete and an invalid code is received, + * then -10 is returned after reading MAXBITS bits. + * + * Format notes: + * + * - The codes as stored in the compressed data are bit-reversed relative to + * a simple integer ordering of codes of the same lengths. Hence below the + * bits are pulled from the compressed data one at a time and used to + * build the code value reversed from what is in the stream in order to + * permit simple integer comparisons for decoding. A table-based decoding + * scheme (as used in zlib) does not need to do this reversal. + * + * - The first code for the shortest length is all zeros. Subsequent codes of + * the same length are simply integer increments of the previous code. When + * moving up a length, a zero bit is appended to the code. For a complete + * code, the last code of the longest length will be all ones. + * + * - Incomplete codes are handled by this decoder, since they are permitted + * in the deflate format. See the format notes for fixed() and dynamic(). + */ +static int decode(state *s, huffman *h) +{ + int len; /* current number of bits in code */ + int code; /* len bits being decoded */ + int first; /* first code of length len */ + int count; /* number of codes of length len */ + int index; /* index of first code of length len in symbol table */ + + // TODO: support chained assigns + // code = first = index = 0; + code = 0; + first = 0; + index = 0; + for (len = 1; len <= MAXBITS; len++) { + code |= bits(s, 1); /* get next bit */ + count = h->count[len]; + if (code - count < first) /* if length len, return symbol */ + return h->symbol[index + (code - first)]; + index += count; /* else update for next length */ + first += count; + first <<= 1; + code <<= 1; + } + return -10; /* ran out of codes */ +} + +/* + * Given the list of code lengths length[0..n-1] representing a canonical + * Huffman code for n symbols, construct the tables required to decode those + * codes. Those tables are the number of codes of each length, and the symbols + * sorted by length, retaining their original order within each length. The + * return value is zero for a complete code set, negative for an over- + * subscribed code set, and positive for an incomplete code set. The tables + * can be used if the return value is zero or positive, but they cannot be used + * if the return value is negative. If the return value is zero, it is not + * possible for decode() using that table to return an error--any stream of + * enough bits will resolve to a symbol. If the return value is positive, then + * it is possible for decode() using that table to return an error for received + * codes past the end of the incomplete lengths. + * + * Not used by decode(), but used for error checking, h->count[0] is the number + * of the n symbols not in the code. So n - h->count[0] is the number of + * codes. This is useful for checking for incomplete codes that have more than + * one symbol, which is an error in a dynamic block. + * + * Assumption: for all i in 0..n-1, 0 <= length[i] <= MAXBITS + * This is assured by the construction of the length arrays in dynamic() and + * fixed() and is not verified by construct(). + * + * Format notes: + * + * - Permitted and expected examples of incomplete codes are one of the fixed + * codes and any code with a single symbol which in deflate is coded as one + * bit instead of zero bits. See the format notes for fixed() and dynamic(). + * + * - Within a given code length, the symbols are kept in ascending order for + * the code bits definition. + */ +static int construct(huffman *h, short *length, int n) +{ + int symbol; /* current symbol when stepping through length[] */ + int len; /* current length when stepping through h->count[] */ + int left; /* number of possible codes left of current length */ + short offs[MAXBITSPLUSONE]; /* offsets in symbol table for each length */ + + /* count number of codes of each length */ + for (len = 0; len <= MAXBITS; len++) + h->count[len] = 0; + for (symbol = 0; symbol < n; symbol++) + // TODO: I get a tokenization error with: + // (h->count[length[symbol]])++; + h->count[length[symbol]]++; /* assumes lengths are within bounds */ + if (h->count[0] == n) /* no codes! */ + return 0; /* complete, but decode() will fail */ + + /* check for an over-subscribed or incomplete set of lengths */ + left = 1; /* one possible code of zero length */ + for (len = 1; len <= MAXBITS; len++) { + left <<= 1; /* one more bit, double codes left */ + left -= h->count[len]; /* deduct count from possible codes */ + if (left < 0) + return left; /* over-subscribed--return negative */ + } /* left > 0 means incomplete */ + + /* generate offsets into symbol table for each length for sorting */ + offs[1] = 0; + for (len = 1; len < MAXBITS; len++) + offs[len + 1] = offs[len] + h->count[len]; + + /* + * put symbols in table sorted by length, by symbol order within each + * length + */ + for (symbol = 0; symbol < n; symbol++) + if (length[symbol] != 0) + h->symbol[offs[length[symbol]]++] = symbol; + + /* return zero for complete set, positive for incomplete set */ + return left; +} + +/* + * Decode literal/length and distance codes until an end-of-block code. + * + * Format notes: + * + * - Compressed data that is after the block type if fixed or after the code + * description if dynamic is a combination of literals and length/distance + * pairs terminated by and end-of-block code. Literals are simply Huffman + * coded bytes. A length/distance pair is a coded length followed by a + * coded distance to represent a string that occurs earlier in the + * uncompressed data that occurs again at the current location. + * + * - Literals, lengths, and the end-of-block code are combined into a single + * code of up to 286 symbols. They are 256 literals (0..255), 29 length + * symbols (257..285), and the end-of-block symbol (256). + * + * - There are 256 possible lengths (3..258), and so 29 symbols are not enough + * to represent all of those. Lengths 3..10 and 258 are in fact represented + * by just a length symbol. Lengths 11..257 are represented as a symbol and + * some number of extra bits that are added as an integer to the base length + * of the length symbol. The number of extra bits is determined by the base + * length symbol. These are in the static arrays below, lens[] for the base + * lengths and lext[] for the corresponding number of extra bits. + * + * - The reason that 258 gets its own symbol is that the longest length is used + * often in highly redundant files. Note that 258 can also be coded as the + * base value 227 plus the maximum extra value of 31. While a good deflate + * should never do this, it is not an error, and should be decoded properly. + * + * - If a length is decoded, including its extra bits if any, then it is + * followed a distance code. There are up to 30 distance symbols. Again + * there are many more possible distances (1..32768), so extra bits are added + * to a base value represented by the symbol. The distances 1..4 get their + * own symbol, but the rest require extra bits. The base distances and + * corresponding number of extra bits are below in the static arrays dist[] + * and dext[]. + * + * - Literal bytes are simply written to the output. A length/distance pair is + * an instruction to copy previously uncompressed bytes to the output. The + * copy is from distance bytes back in the output stream, copying for length + * bytes. + * + * - Distances pointing before the beginning of the output data are not + * permitted. + * + * - Overlapped copies, where the length is greater than the distance, are + * allowed and common. For example, a distance of one and a length of 258 + * simply copies the last byte 258 times. A distance of four and a length of + * twelve copies the last four bytes three times. A simple forward copy + * ignoring whether the length is greater than the distance or not implements + * this correctly. You should not use memcpy() since its behavior is not + * defined for overlapped arrays. You should not use memmove() or bcopy() + * since though their behavior -is- defined for overlapping arrays, it is + * defined to do the wrong thing in this case. + */ +static short lens[29] = { /* Size base for length codes 257..285 */ + 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, + 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258}; +static short lext[29] = { /* Extra bits for length codes 257..285 */ + 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, + 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0}; +static short dists[30] = { /* Offset base for distance codes 0..29 */ + 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, + 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, + 8193, 12289, 16385, 24577}; +static short dext[30] = { /* Extra bits for distance codes 0..29 */ + 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, + 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, + 12, 12, 13, 13}; +static int codes(state *s, huffman *lencode, huffman *distcode) +{ + int symbol; /* decoded symbol */ + int len; /* length for copy */ + unsigned int dist; /* distance for copy */ + + /* decode literals and length/distance pairs */ + do { + symbol = decode(s, lencode); + if (symbol < 0) + return symbol; /* invalid symbol */ + if (symbol < 256) { /* literal: symbol is the byte */ + /* write out the literal */ + if (s->out != NULL) { + if (s->outcnt == s->outlen) + return 1; + s->out[s->outcnt] = symbol; + } + s->outcnt++; + } + else if (symbol > 256) { /* length */ + /* get and compute length */ + symbol -= 257; + if (symbol >= 29) + return -10; /* invalid fixed code */ + len = lens[symbol] + bits(s, lext[symbol]); + + /* get and check distance */ + symbol = decode(s, distcode); + if (symbol < 0) + return symbol; /* invalid symbol */ + dist = dists[symbol] + bits(s, dext[symbol]); + if (dist > s->outcnt) + return -11; /* distance too far back */ + + /* copy length bytes from distance bytes back */ + if (s->out != NULL) { + if (s->outcnt + len > s->outlen) + return 1; + while (len--) { + // TODO: add "cond ? x : y" form + if (dist > s->outcnt) + s->out[s->outcnt] = 0; + else + s->out[s->outcnt] = s->out[s->outcnt - dist]; + s->outcnt++; + } + } + else + s->outcnt += len; + } + } while (symbol != 256); /* end of block symbol */ + + /* done with a valid fixed or dynamic block */ + return 0; +} + +/* + * Process a fixed codes block. + * + * Format notes: + * + * - This block type can be useful for compressing small amounts of data for + * which the size of the code descriptions in a dynamic block exceeds the + * benefit of custom codes for that block. For fixed codes, no bits are + * spent on code descriptions. Instead the code lengths for literal/length + * codes and distance codes are fixed. The specific lengths for each symbol + * can be seen in the "for" loops below. + * + * - The literal/length code is complete, but has two symbols that are invalid + * and should result in an error if received. This cannot be implemented + * simply as an incomplete code since those two symbols are in the "middle" + * of the code. They are eight bits long and the longest literal/length\ + * code is nine bits. Therefore the code must be constructed with those + * symbols, and the invalid symbols must be detected after decoding. + * + * - The fixed distance codes also have two invalid symbols that should result + * in an error if received. Since all of the distance codes are the same + * length, this can be implemented as an incomplete code. Then the invalid + * codes are detected while decoding. + */ + +static int virgin = 1; +static short lencnt[MAXBITSPLUSONE], lensym[FIXLCODES]; +static short distcnt[MAXBITSPLUSONE], distsym[MAXDCODES]; +static huffman lencode, distcode; + +static int fixed(state *s) +{ + int symbol; + short lengths[FIXLCODES]; + + /* build fixed huffman tables if first call (may not be thread safe) */ + if (virgin) { + /* construct lencode and distcode */ + lencode.count = lencnt; + lencode.symbol = lensym; + distcode.count = distcnt; + distcode.symbol = distsym; + + /* literal/length table */ + for (symbol = 0; symbol < 144; symbol++) + lengths[symbol] = 8; + // TODO: fix error when for()'s initialization is empty + // meanwhile: dummy "symbol=symbol" + for (symbol=symbol; symbol < 256; symbol++) + lengths[symbol] = 9; + for (symbol=symbol; symbol < 280; symbol++) + lengths[symbol] = 7; + for (symbol=symbol; symbol < FIXLCODES; symbol++) + lengths[symbol] = 8; + construct(&lencode, lengths, FIXLCODES); + + /* distance table */ + for (symbol = 0; symbol < MAXDCODES; symbol++) + lengths[symbol] = 5; + construct(&distcode, lengths, MAXDCODES); + + /* do this just once */ + virgin = 0; + } + + /* decode data until end-of-block code */ + return codes(s, &lencode, &distcode); +} + +/* + * Process a dynamic codes block. + * + * Format notes: + * + * - A dynamic block starts with a description of the literal/length and + * distance codes for that block. New dynamic blocks allow the compressor to + * rapidly adapt to changing data with new codes optimized for that data. + * + * - The codes used by the deflate format are "canonical", which means that + * the actual bits of the codes are generated in an unambiguous way simply + * from the number of bits in each code. Therefore the code descriptions + * are simply a list of code lengths for each symbol. + * + * - The code lengths are stored in order for the symbols, so lengths are + * provided for each of the literal/length symbols, and for each of the + * distance symbols. + * + * - If a symbol is not used in the block, this is represented by a zero as + * as the code length. This does not mean a zero-length code, but rather + * that no code should be created for this symbol. There is no way in the + * deflate format to represent a zero-length code. + * + * - The maximum number of bits in a code is 15, so the possible lengths for + * any code are 1..15. + * + * - The fact that a length of zero is not permitted for a code has an + * interesting consequence. Normally if only one symbol is used for a given + * code, then in fact that code could be represented with zero bits. However + * in deflate, that code has to be at least one bit. So for example, if + * only a single distance base symbol appears in a block, then it will be + * represented by a single code of length one, in particular one 0 bit. This + * is an incomplete code, since if a 1 bit is received, it has no meaning, + * and should result in an error. So incomplete distance codes of one symbol + * should be permitted, and the receipt of invalid codes should be handled. + * + * - It is also possible to have a single literal/length code, but that code + * must be the end-of-block code, since every dynamic block has one. This + * is not the most efficient way to create an empty block (an empty fixed + * block is fewer bits), but it is allowed by the format. So incomplete + * literal/length codes of one symbol should also be permitted. + * + * - If there are only literal codes and no lengths, then there are no distance + * codes. This is represented by one distance code with zero bits. + * + * - The list of up to 286 length/literal lengths and up to 30 distance lengths + * are themselves compressed using Huffman codes and run-length encoding. In + * the list of code lengths, a 0 symbol means no code, a 1..15 symbol means + * that length, and the symbols 16, 17, and 18 are run-length instructions. + * Each of 16, 17, and 18 are followed by extra bits to define the length of + * the run. 16 copies the last length 3 to 6 times. 17 represents 3 to 10 + * zero lengths, and 18 represents 11 to 138 zero lengths. Unused symbols + * are common, hence the special coding for zero lengths. + * + * - The symbols for 0..18 are Huffman coded, and so that code must be + * described first. This is simply a sequence of up to 19 three-bit values + * representing no code (0) or the code length for that symbol (1..7). + * + * - A dynamic block starts with three fixed-size counts from which is computed + * the number of literal/length code lengths, the number of distance code + * lengths, and the number of code length code lengths (ok, you come up with + * a better name!) in the code descriptions. For the literal/length and + * distance codes, lengths after those provided are considered zero, i.e. no + * code. The code length code lengths are received in a permuted order (see + * the order[] array below) to make a short code length code length list more + * likely. As it turns out, very short and very long codes are less likely + * to be seen in a dynamic code description, hence what may appear initially + * to be a peculiar ordering. + * + * - Given the number of literal/length code lengths (nlen) and distance code + * lengths (ndist), then they are treated as one long list of nlen + ndist + * code lengths. Therefore run-length coding can and often does cross the + * boundary between the two sets of lengths. + * + * - So to summarize, the code description at the start of a dynamic block is + * three counts for the number of code lengths for the literal/length codes, + * the distance codes, and the code length codes. This is followed by the + * code length code lengths, three bits each. This is used to construct the + * code length code which is used to read the remainder of the lengths. Then + * the literal/length code lengths and distance lengths are read as a single + * set of lengths using the code length codes. Codes are constructed from + * the resulting two sets of lengths, and then finally you can start + * decoding actual compressed data in the block. + * + * - For reference, a "typical" size for the code description in a dynamic + * block is around 80 bytes. + */ +static short order[19] = /* permutation of code length codes */ + {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; +static int dynamic(state *s) +{ + int nlen, ndist, ncode; /* number of lengths in descriptor */ + int index; /* index of lengths[] */ + int err; /* construct() return value */ + short lengths[MAXCODES]; /* descriptor code lengths */ + short lencnt[MAXBITSPLUSONE], lensym[MAXLCODES]; /* lencode memory */ + short distcnt[MAXBITSPLUSONE], distsym[MAXDCODES]; /* distcode memory */ + huffman lencode, distcode; /* length and distance codes */ + int symbol; /* decoded value */ + int len; /* last length to repeat */ + + /* construct lencode and distcode */ + lencode.count = lencnt; + lencode.symbol = lensym; + distcode.count = distcnt; + distcode.symbol = distsym; + + /* get number of lengths in each table, check lengths */ + nlen = bits(s, 5) + 257; + ndist = bits(s, 5) + 1; + ncode = bits(s, 4) + 4; + if (nlen > MAXLCODES || ndist > MAXDCODES) + return -3; /* bad counts */ + + /* read code length code lengths (really), missing lengths are zero */ + for (index = 0; index < ncode; index++) + lengths[order[index]] = bits(s, 3); + // TODO: empty for init. dummy "index=index" + for (index = index; index < 19; index++) + lengths[order[index]] = 0; + + /* build huffman table for code lengths codes (use lencode temporarily) */ + err = construct(&lencode, lengths, 19); + if (err != 0) /* require complete code set here */ + return -4; + + /* read length/literal and distance code length tables */ + index = 0; + while (index < nlen + ndist) { + symbol = decode(s, &lencode); + if (symbol < 0) + return symbol; /* invalid symbol */ + if (symbol < 16) /* length in 0..15 */ + lengths[index++] = symbol; + else { /* repeat instruction */ + len = 0; /* assume repeating zeros */ + if (symbol == 16) { /* repeat last length 3..6 times */ + if (index == 0) + return -5; /* no last length! */ + len = lengths[index - 1]; /* last length */ + symbol = 3 + bits(s, 2); + } + else if (symbol == 17) /* repeat zero 3..10 times */ + symbol = 3 + bits(s, 3); + else /* == 18, repeat zero 11..138 times */ + symbol = 11 + bits(s, 7); + if (index + symbol > nlen + ndist) + return -6; /* too many lengths! */ + while (symbol--) /* repeat last or zero symbol times */ + lengths[index++] = len; + } + } + + /* check for end-of-block code -- there better be one! */ + if (lengths[256] == 0) + return -9; + + /* build huffman table for literal/length codes */ + err = construct(&lencode, lengths, nlen); + if (err && (err < 0 || nlen != lencode.count[0] + lencode.count[1])) + return -7; /* incomplete code ok only for single length 1 code */ + + /* build huffman table for distance codes */ + err = construct(&distcode, lengths + nlen, ndist); + if (err && (err < 0 || ndist != distcode.count[0] + distcode.count[1])) + return -8; /* incomplete code ok only for single length 1 code */ + + /* decode data until end-of-block code */ + return codes(s, &lencode, &distcode); +} + +/* + * Inflate source to dest. On return, destlen and sourcelen are updated to the + * size of the uncompressed data and the size of the deflate data respectively. + * On success, the return value of puff() is zero. If there is an error in the + * source data, i.e. it is not in the deflate format, then a negative value is + * returned. If there is not enough input available or there is not enough + * output space, then a positive error is returned. In that case, destlen and + * sourcelen are not updated to facilitate retrying from the beginning with the + * provision of more input data or more output space. In the case of invalid + * inflate data (a negative error), the dest and source pointers are updated to + * facilitate the debugging of deflators. + * + * puff() also has a mode to determine the size of the uncompressed output with + * no output written. For this dest must be (unsigned char *)0. In this case, + * the input value of *destlen is ignored, and on return *destlen is set to the + * size of the uncompressed output. + * + * The return codes are: + * + * 2: available inflate data did not terminate + * 1: output space exhausted before completing inflate + * 0: successful inflate + * -1: invalid block type (type == 3) + * -2: stored block length did not match one's complement + * -3: dynamic block code description: too many length or distance codes + * -4: dynamic block code description: code lengths codes incomplete + * -5: dynamic block code description: repeat lengths with no first length + * -6: dynamic block code description: repeat more than specified lengths + * -7: dynamic block code description: invalid literal/length code lengths + * -8: dynamic block code description: invalid distance code lengths + * -9: dynamic block code description: missing end-of-block code + * -10: invalid literal/length or distance code in fixed or dynamic block + * -11: distance is too far back in fixed or dynamic block + * + * Format notes: + * + * - Three bits are read for each block to determine the kind of block and + * whether or not it is the last block. Then the block is decoded and the + * process repeated if it was not the last block. + * + * - The leftover bits in the last byte of the deflate data after the last + * block (if it was a fixed or dynamic block) are undefined and have no + * expected values to check. + */ +int puff(unsigned char *dest, /* pointer to destination pointer */ + unsigned int *destlen, /* amount of output space */ + unsigned char *source, /* pointer to source data pointer */ + unsigned int *sourcelen) /* amount of input available */ +{ + state s; /* input/output state */ + int last, type; /* block information */ + int err; /* return value */ + + /* initialize output state */ + s.out = dest; + s.outlen = *destlen; /* ignored if dest is NULL */ + s.outcnt = 0; + + /* initialize input state */ + s.in = source; + s.inlen = *sourcelen; + s.incnt = 0; + s.bitbuf = 0; + s.bitcnt = 0; + + /* process blocks until last block or error */ + do { + last = bits(&s, 1); /* one if last block */ + type = bits(&s, 2); /* block type 0..3 */ + if (type == 0) err = stored(&s); + else if (type == 1) err = fixed(&s); + else if (type == 2) err = dynamic(&s); + else err = -1; + if (err != 0) + break; /* return with error */ + } while (!last); + + /* update the lengths and return */ + if (err <= 0) { + *destlen = s.outcnt; + *sourcelen = s.incnt; + } + return err; +}diff --git a/fs/ar/puff.fs b/fs/ar/puff.fs@@ -0,0 +1,2 @@ +?f<< /comp/c/lib.fs +cc<< /ar/puff.cdiff --git a/fs/ar/ungz.c b/fs/ar/ungz.c@@ -1,933 +0,0 @@ -/* Source: https://github.com/oriansj/mescc-tools-extra - * License: /license/oriansj-ungz.txt - */ - -typedef unsigned int size_t; -typedef int long; - -/* - * Maximums for allocations and loops. It is not useful to change these -- - * they are fixed by the deflate format. - */ -/* maximum bits in a code */ -#define MAXBITS 15 -/* TODO: allow constant expressions array typedefs, for example MAXBITS+1 */ -#define MAXBITSPLUSONE 16 -/* maximum number of literal/length codes */ -#define MAXLCODES 286 -/* maximum number of distance codes */ -#define MAXDCODES 30 -/* maximum codes lengths to read (MAXLCODES+MAXDCODES) */ -#define MAXCODES 316 -/* number of fixed literal/length codes */ -#define FIXLCODES 288 - -/* input and output state */ -struct state { - /* output state */ - char *out; /* output buffer */ - size_t outlen; /* available space at out */ - size_t outcnt; /* bytes written to out so far */ - - /* input state */ - char *in; /* input buffer */ - size_t inlen; /* available input at in */ - size_t incnt; /* bytes read so far */ - int bitbuf; /* bit buffer */ - int bitcnt; /* number of bits in bit buffer */ -}; - -/* - * Return need bits from the input stream. This always leaves less than - * eight bits in the buffer. bits() works properly for need == 0. - * - * Format notes: - * - * - Bits are stored in bytes from the least significant bit to the most - * significant bit. Therefore bits are dropped from the bottom of the bit - * buffer, using shift right, and new bytes are appended to the top of the - * bit buffer, using shift left. - */ -static int bits(state *s, int need) -{ - long val; /* bit accumulator (can use up to 20 bits) */ - long hold; - - /* load at least need bits into val */ - val = s->bitbuf; - while (s->bitcnt < need) - { - if (s->incnt == s->inlen) - { - fputs("out of input\n", ConsoleOut()); - abort(); - } - hold = (s->in[s->incnt] & $FF); - s->incnt = s->incnt + 1; - val = val | (hold << s->bitcnt); /* load eight bits */ - s->bitcnt = s->bitcnt + 8; - } - - /* drop need bits and update buffer, always zero to seven bits left */ - s->bitbuf = (val >> need); - s->bitcnt = s->bitcnt - need; - - /* return need bits, zeroing the bits above that */ - val = (val & ((1 << need) - 1)); - return val; -} - -/* - * Process a stored block. - * - * Format notes: - * - * - After the two-bit stored block type (00), the stored block length and - * stored bytes are byte-aligned for fast copying. Therefore any leftover - * bits in the byte that has the last bit of the type, as many as seven, are - * discarded. The value of the discarded bits are not defined and should not - * be checked against any expectation. - * - * - The second inverted copy of the stored block length does not have to be - * checked, but it's probably a good idea to do so anyway. - * - * - A stored block can have zero length. This is sometimes used to byte-align - * subsets of the compressed data for random access or partial recovery. - */ -static int stored(state *s) -{ - unsigned int len; /* length of stored block */ - - /* discard leftover bits from current byte (assumes s->bitcnt < 8) */ - s->bitbuf = 0; - s->bitcnt = 0; - - /* get length and check against its one's complement */ - if ((s->incnt + 4) > s->inlen) return 2; /* not enough input */ - len = s->in[s->incnt]; - s->incnt = s->incnt + 1; - len = len | (s->in[s->incnt] << 8); - s->incnt = s->incnt + 1; - if(s->in[s->incnt] != (~len & $ff)) return -2; /* didn't match complement! */ - s->incnt = s->incnt + 1; - if(s->in[s->incnt] != ((~len >> 8) & $ff)) return -2; /* didn't match complement! */ - s->incnt = s->incnt + 1; - - /* copy len bytes from in to out */ - if ((s->incnt + len) > s->inlen) return 2; /* not enough input */ - if (s->out != 0) - { - if ((s->outcnt + len) > s->outlen) return 1; /* not enough output space */ - while (0 != len) - { - len = len - 1; - s->out[s->outcnt] = s->in[s->incnt]; - s->outcnt = s->outcnt + 1; - s->incnt = s->incnt + 1; - } - } - else - { /* just scanning */ - s->outcnt = s->outcnt + len; - s->incnt = s->incnt + len; - } - - /* done with a valid stored block */ - return 0; -} - -/* - * Huffman code decoding tables. count[1..MAXBITS] is the number of symbols of - * each length, which for a canonical code are stepped through in order. - * symbol[] are the symbol values in canonical order, where the number of - * entries is the sum of the counts in count[]. The decoding process can be - * seen in the function decode() below. - */ -struct huffman -{ - int count[MAXBITSPLUSONE]; /* number of symbols of each length */ - int symbol[FIXLCODES]; /* canonically ordered symbols */ -}; - -/* - * Decode a code from the stream s using huffman table h. Return the symbol or - * a negative value if there is an error. If all of the lengths are zero, i.e. - * an empty code, or if the code is incomplete and an invalid code is received, - * then -10 is returned after reading MAXBITS bits. - * - * Format notes: - * - * - The codes as stored in the compressed data are bit-reversed relative to - * a simple integer ordering of codes of the same lengths. Hence below the - * bits are pulled from the compressed data one at a time and used to - * build the code value reversed from what is in the stream in order to - * permit simple integer comparisons for decoding. A table-based decoding - * scheme (as used in zlib) does not need to do this reversal. - * - * - The first code for the shortest length is all zeros. Subsequent codes of - * the same length are simply integer increments of the previous code. When - * moving up a length, a zero bit is appended to the code. For a complete - * code, the last code of the longest length will be all ones. - * - * - Incomplete codes are handled by this decoder, since they are permitted - * in the deflate format. See the format notes for fixed() and dynamic(). - */ -int decode(state *s, huffman *h) -{ - int len; /* current number of bits in code */ - int code = 0; /* len bits being decoded */ - int first = 0; /* first code of length len */ - int count; /* number of codes of length len */ - int index = 0; /* index of first code of length len in symbol table */ - long hold; - - for (len = 1; len <= MAXBITS; len = len + 1) - { - hold = bits(s, 1); /* get next bit */ - code = code | hold; - count = h->count[len]; - if ((code - count) < first) - { - hold = index + (code - first); - return h->symbol[hold]; /* if length len, return symbol */ - } - index = index + count; /* else update for next length */ - first = first + count; - first = first << 1; - code = code << 1; - } - return -10; /* ran out of codes */ -} - -/* - * Given the list of code lengths length[0..n-1] representing a canonical - * Huffman code for n symbols, construct the tables required to decode those - * codes. Those tables are the number of codes of each length, and the symbols - * sorted by length, retaining their original order within each length. The - * return value is zero for a complete code set, negative for an over- - * subscribed code set, and positive for an incomplete code set. The tables - * can be used if the return value is zero or positive, but they cannot be used - * if the return value is negative. If the return value is zero, it is not - * possible for decode() using that table to return an error--any stream of - * enough bits will resolve to a symbol. If the return value is positive, then - * it is possible for decode() using that table to return an error for received - * codes past the end of the incomplete lengths. - * - * Not used by decode(), but used for error checking, h->count[0] is the number - * of the n symbols not in the code. So n - h->count[0] is the number of - * codes. This is useful for checking for incomplete codes that have more than - * one symbol, which is an error in a dynamic block. - * - * Assumption: for all i in 0..n-1, 0 <= length[i] <= MAXBITS - * This is assured by the construction of the length arrays in dynamic() and - * fixed() and is not verified by construct(). - * - * Format notes: - * - * - Permitted and expected examples of incomplete codes are one of the fixed - * codes and any code with a single symbol which in deflate is coded as one - * bit instead of zero bits. See the format notes for fixed() and dynamic(). - * - * - Within a given code length, the symbols are kept in ascending order for - * the code bits definition. - */ -int construct(huffman *h, int *length, int n) -{ - int symbol; /* current symbol when stepping through length[] */ - int len; /* current length when stepping through h->count[] */ - int left; /* number of possible codes left of current length */ - int offs[MAXBITSPLUSONE]; /* offsets in symbol table for each length */ - long hold; - - /* count number of codes of each length */ - for (len = 0; len <= MAXBITS; len = len + 1) - { - h->count[len] = 0; - } - - for (symbol = 0; symbol < n; symbol = symbol + 1) - { - hold = length[symbol]; - h->count[hold] = h->count[hold] + 1; /* assumes lengths are within bounds */ - } - - if (h->count[0] == n) return 0; /* no codes! complete, but decode() will fail */ - - /* check for an over-subscribed or incomplete set of lengths */ - left = 1; /* one possible code of zero length */ - for (len = 1; len <= MAXBITS; len = len + 1) - { - left = left << 1; /* one more bit, double codes left */ - left = left - h->count[len]; /* deduct count from possible codes */ - if (left < 0) return left; /* over-subscribed--return negative */ - } /* left > 0 means incomplete */ - - /* generate offsets into symbol table for each length for sorting */ - offs[1] = 0; - for (len = 1; len < MAXBITS; len = len + 1) - { - offs[len + 1] = offs[len] + h->count[len]; - } - - /* - * put symbols in table sorted by length, by symbol order within each - * length - */ - for (symbol = 0; symbol < n; symbol = symbol + 1) - { - if (length[symbol] != 0) - { - hold = length[symbol]; - hold = offs[hold]; - h->symbol[hold] = symbol; - hold = length[symbol]; - offs[hold] = offs[hold] + 1; - } - } - - /* return zero for complete set, positive for incomplete set */ - return left; -} - -static int codes_lens[30] = { - 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59, 67, - 83, 99, 115, 131, 163, 195, 227, 258, 0}; - -static int codes_lext[30] = { - 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, - 5, 5, 5, 5, 0, 0}; - -static int codes_dists[31] = { - 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513, - 769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577, 0}; - -static int codes_dext[31] = { - 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, - 11, 11, 12, 12, 13, 13, 0}; - -int codes(state *s, huffman *lencode, huffman *distcode) -{ - int symbol; /* decoded symbol */ - int len; /* length for copy */ - unsigned int dist; /* distance for copy */ - - /* decode literals and length/distance pairs */ - do - { - symbol = decode(s, lencode); - if (symbol < 0) return symbol; /* invalid symbol */ - if (symbol < 256) /* literal: symbol is the byte */ - { - /* write out the literal */ - if (s->out != 0) - { - if (s->outcnt == s->outlen) return 1; - s->out[s->outcnt] = symbol; - } - s->outcnt = s->outcnt + 1; - } - else if (symbol > 256) /* length */ - { - /* get and compute length */ - symbol = symbol - 257; - if (symbol >= 29) return -10; /* invalid fixed code */ - len = codes_lens[symbol] + bits(s, codes_lext[symbol]); - - /* get and check distance */ - symbol = decode(s, distcode); - if (symbol < 0) return symbol; /* invalid symbol */ - dist = codes_dists[symbol] + bits(s, codes_dext[symbol]); - if (dist > s->outcnt) return -11; /* distance too far back */ - - /* copy length bytes from distance bytes back */ - if (s->out != 0) - { - if (s->outcnt + len > s->outlen) return 1; - while (0 != len) - { - len = len - 1; - if(dist > s->outcnt) s->out[s->outcnt] = 0; - else s->out[s->outcnt] = s->out[s->outcnt - dist]; - s->outcnt = s->outcnt + 1; - } - } - else s->outcnt = s->outcnt + len; - } - } while (symbol != 256); /* end of block symbol */ - - /* done with a valid fixed or dynamic block */ - return 0; -} - -/* - * Process a fixed codes block. - * - * Format notes: - * - * - This block type can be useful for compressing small amounts of data for - * which the size of the code descriptions in a dynamic block exceeds the - * benefit of custom codes for that block. For fixed codes, no bits are - * spent on code descriptions. Instead the code lengths for literal/length - * codes and distance codes are fixed. The specific lengths for each symbol - * can be seen in the "for" loops below. - * - * - The literal/length code is complete, but has two symbols that are invalid - * and should result in an error if received. This cannot be implemented - * simply as an incomplete code since those two symbols are in the "middle" - * of the code. They are eight bits long and the longest literal/length\ - * code is nine bits. Therefore the code must be constructed with those - * symbols, and the invalid symbols must be detected after decoding. - * - * - The fixed distance codes also have two invalid symbols that should result - * in an error if received. Since all of the distance codes are the same - * length, this can be implemented as an incomplete code. Then the invalid - * codes are detected while decoding. - */ -int fixed(state *s) -{ - huffman lencode; - huffman distcode; - int hold; - - /* build fixed huffman tables if first call (may not be thread safe) */ - int symbol; - int lengths[FIXLCODES]; - - /* literal/length table */ - for (symbol = 0; symbol < 144; symbol = symbol + 1) - { - lengths[symbol] = 8; - } - - while(symbol < 256) - { - lengths[symbol] = 9; - symbol = symbol + 1; - } - - while(symbol < 280) - { - lengths[symbol] = 7; - symbol = symbol + 1; - } - - while(symbol < FIXLCODES) - { - lengths[symbol] = 8; - symbol = symbol + 1; - } - - construct(&lencode, lengths, FIXLCODES); - - /* distance table */ - for (symbol = 0; symbol < MAXDCODES; symbol = symbol + 1) - { - lengths[symbol] = 5; - } - - construct(&distcode, lengths, MAXDCODES); - - /* decode data until end-of-block code */ - hold = codes(s, &lencode, &distcode); - return hold; -} - -/* - * Process a dynamic codes block. - * - * Format notes: - * - * - A dynamic block starts with a description of the literal/length and - * distance codes for that block. New dynamic blocks allow the compressor to - * rapidly adapt to changing data with new codes optimized for that data. - * - * - The codes used by the deflate format are "canonical", which means that - * the actual bits of the codes are generated in an unambiguous way simply - * from the number of bits in each code. Therefore the code descriptions - * are simply a list of code lengths for each symbol. - * - * - The code lengths are stored in order for the symbols, so lengths are - * provided for each of the literal/length symbols, and for each of the - * distance symbols. - * - * - If a symbol is not used in the block, this is represented by a zero as - * as the code length. This does not mean a zero-length code, but rather - * that no code should be created for this symbol. There is no way in the - * deflate format to represent a zero-length code. - * - * - The maximum number of bits in a code is 15, so the possible lengths for - * any code are 1..15. - * - * - The fact that a length of zero is not permitted for a code has an - * interesting consequence. Normally if only one symbol is used for a given - * code, then in fact that code could be represented with zero bits. However - * in deflate, that code has to be at least one bit. So for example, if - * only a single distance base symbol appears in a block, then it will be - * represented by a single code of length one, in particular one 0 bit. This - * is an incomplete code, since if a 1 bit is received, it has no meaning, - * and should result in an error. So incomplete distance codes of one symbol - * should be permitted, and the receipt of invalid codes should be handled. - * - * - It is also possible to have a single literal/length code, but that code - * must be the end-of-block code, since every dynamic block has one. This - * is not the most efficient way to create an empty block (an empty fixed - * block is fewer bits), but it is allowed by the format. So incomplete - * literal/length codes of one symbol should also be permitted. - * - * - If there are only literal codes and no lengths, then there are no distance - * codes. This is represented by one distance code with zero bits. - * - * - The list of up to 286 length/literal lengths and up to 30 distance lengths - * are themselves compressed using Huffman codes and run-length encoding. In - * the list of code lengths, a 0 symbol means no code, a 1..15 symbol means - * that length, and the symbols 16, 17, and 18 are run-length instructions. - * Each of 16, 17, and 18 are follwed by extra bits to define the length of - * the run. 16 copies the last length 3 to 6 times. 17 represents 3 to 10 - * zero lengths, and 18 represents 11 to 138 zero lengths. Unused symbols - * are common, hence the special coding for zero lengths. - * - * - The symbols for 0..18 are Huffman coded, and so that code must be - * described first. This is simply a sequence of up to 19 three-bit values - * representing no code (0) or the code length for that symbol (1..7). - * - * - A dynamic block starts with three fixed-size counts from which is computed - * the number of literal/length code lengths, the number of distance code - * lengths, and the number of code length code lengths (ok, you come up with - * a better name!) in the code descriptions. For the literal/length and - * distance codes, lengths after those provided are considered zero, i.e. no - * code. The code length code lengths are received in a permuted order (see - * the order[] array below) to make a short code length code length list more - * likely. As it turns out, very short and very long codes are less likely - * to be seen in a dynamic code description, hence what may appear initially - * to be a peculiar ordering. - * - * - Given the number of literal/length code lengths (nlen) and distance code - * lengths (ndist), then they are treated as one long list of nlen + ndist - * code lengths. Therefore run-length coding can and often does cross the - * boundary between the two sets of lengths. - * - * - So to summarize, the code description at the start of a dynamic block is - * three counts for the number of code lengths for the literal/length codes, - * the distance codes, and the code length codes. This is followed by the - * code length code lengths, three bits each. This is used to construct the - * code length code which is used to read the remainder of the lengths. Then - * the literal/length code lengths and distance lengths are read as a single - * set of lengths using the code length codes. Codes are constructed from - * the resulting two sets of lengths, and then finally you can start - * decoding actual compressed data in the block. - * - * - For reference, a "typical" size for the code description in a dynamic - * block is around 80 bytes. - */ - -static int dynamic_order[20] = { - 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15, 0}; - -static int dynamic(state *s) -{ - int nlen; - int ndist; - int ncode; /* number of lengths in descriptor */ - int index; /* index of lengths[] */ - int err; /* construct() return value */ - int lengths[MAXCODES]; - huffman lencode; - huffman distcode; - long hold; - int* set; - int symbol; /* decoded value */ - int len; /* last length to repeat */ - - /* get number of lengths in each table, check lengths */ - nlen = bits(s, 5) + 257; - ndist = bits(s, 5) + 1; - ncode = bits(s, 4) + 4; - if (nlen > MAXLCODES) return -3; /* bad counts */ - if(ndist > MAXDCODES) return -3; /* bad counts */ - - /* read code length code lengths (really), missing lengths are zero */ - for (index = 0; index < ncode; index = index + 1) - { - hold = dynamic_order[index]; - lengths[hold] = bits(s, 3); - } - - while(index < 19) - { - hold = dynamic_order[index]; - lengths[hold] = 0; - index = index + 1; - } - - /* build huffman table for code lengths codes (use lencode temporarily) */ - err = construct(&lencode, lengths, 19); - if (err != 0) return -4; /* require complete code set here */ - - /* read length/literal and distance code length tables */ - index = 0; - while (index < (nlen + ndist)) - { - symbol = decode(s, &lencode); - if (symbol < 0) return symbol; /* invalid symbol */ - - if (symbol < 16) /* length in 0..15 */ - { - lengths[index] = symbol; - index = index + 1; - } - else /* repeat instruction */ - { - len = 0; /* assume repeating zeros */ - if (symbol == 16) /* repeat last length 3..6 times */ - { - if (index == 0) return -5; /* no last length! */ - len = lengths[index - 1]; /* last length */ - symbol = 3 + bits(s, 2); - } - else if (symbol == 17) symbol = 3 + bits(s, 3); /* repeat zero 3..10 times */ - else symbol = 11 + bits(s, 7); /* == 18, repeat zero 11..138 times */ - - if ((index + symbol) > (nlen + ndist)) return -6; /* too many lengths! */ - - while(0 != symbol) /* repeat last or zero symbol times */ - { - lengths[index] = len; - index = index + 1; - symbol = symbol - 1; - } - } - } - - /* check for end-of-block code -- there better be one! */ - if (lengths[256] == 0) return -9; - - /* build huffman table for literal/length codes */ - err = construct(&lencode, lengths, nlen); - - /* incomplete code ok only for single length 1 code */ - if (err < 0) return -7; - if((0 != err) && (nlen != (lencode.count[0] + lencode.count[1]))) return -7; - - /* build huffman table for distance codes */ - set = lengths + nlen; - err = construct(&distcode, set, ndist); - - /* incomplete code ok only for single length 1 code */ - if (err < 0) return -8; - if((0 != err) && (ndist != (distcode.count[0] + distcode.count[1]))) return -8; - - /* decode data until end-of-block code */ - hold = codes(s, &lencode, &distcode); - return hold; -} - -/* - * Inflate source to dest. On return, destlen and sourcelen are updated to the - * size of the uncompressed data and the size of the deflate data respectively. - * On success, the return value of puff() is zero. If there is an error in the - * source data, i.e. it is not in the deflate format, then a negative value is - * returned. If there is not enough input available or there is not enough - * output space, then a positive error is returned. In that case, destlen and - * sourcelen are not updated to facilitate retrying from the beginning with the - * provision of more input data or more output space. In the case of invalid - * inflate data (a negative error), the dest and source pointers are updated to - * facilitate the debugging of deflators. - * - * puff() also has a mode to determine the size of the uncompressed output with - * no output written. For this dest must be (unsigned char *)0. In this case, - * the input value of *destlen is ignored, and on return *destlen is set to the - * size of the uncompressed output. - * - * The return codes are: - * - * 2: available inflate data did not terminate - * 1: output space exhausted before completing inflate - * 0: successful inflate - * -1: invalid block type (type == 3) - * -2: stored block length did not match one's complement - * -3: dynamic block code description: too many length or distance codes - * -4: dynamic block code description: code lengths codes incomplete - * -5: dynamic block code description: repeat lengths with no first length - * -6: dynamic block code description: repeat more than specified lengths - * -7: dynamic block code description: invalid literal/length code lengths - * -8: dynamic block code description: invalid distance code lengths - * -9: dynamic block code description: missing end-of-block code - * -10: invalid literal/length or distance code in fixed or dynamic block - * -11: distance is too far back in fixed or dynamic block - * - * Format notes: - * - * - Three bits are read for each block to determine the kind of block and - * whether or not it is the last block. Then the block is decoded and the - * process repeated if it was not the last block. - * - * - The leftover bits in the last byte of the deflate data after the last - * block (if it was a fixed or dynamic block) are undefined and have no - * expected values to check. - */ - -struct puffer -{ - int error; - size_t destlen; - size_t sourcelen; -}; - -static puffer _puffer; - -puffer* puff(char* dest, size_t destlen, char* source, size_t sourcelen) -{ - state s; /* input/output state */ - int last; - int type; /* block information */ - int err; /* return value */ - - /* initialize output state */ - s.out = dest; - s.outlen = destlen; /* ignored if dest is NIL */ - s.outcnt = 0; - - /* initialize input state */ - s.in = source; - s.inlen = sourcelen; - s.incnt = 0; - s.bitbuf = 0; - s.bitcnt = 0; - - /* process blocks until last block or error */ - do - { - last = bits(&s, 1); /* one if last block */ - type = bits(&s, 2); /* block type 0..3 */ - - if(0 == type) - { - err = stored(&s); - } - else if(1 == type) - { - err = fixed(&s); - } - else if(2 == type) - { - err = dynamic(&s); - } - else err = -1; - - if (err != 0) break; /* return with error */ - } while (!last); - - /* update the lengths and return */ - _puffer.error = err; - _puffer.destlen = s.outcnt; - _puffer.sourcelen = s.incnt; - return &_puffer; -} - -void write_blob(char* s, int start, int len, File *f) -{ - char* table = "0123456789ABCDEF"; - int i = s[start] & $FF; - - if(start > len) return; - - fputc(table[(i >> 4)], f); - fputc(table[(i & $F)], f); - fputc(' ', f); - - if(start == len) fputc($0a, f); - else fputc(' ', f); - write_blob(s, start + 1, len, f); -} - -#define FTEXT $01 -#define FHCRC $02 -#define FEXTRA $04 -#define FNAME $08 -#define FCOMMENT $10 -#define MAXGZSZ $10000 -#define FNAMEMAXSZ $100 -#define FCOMMENTMAXSZ $100 -// TODO: can't #define right after a // comment - -static char _block_buf[MAXGZSZ]; -static char _extra_buf[MAXGZSZ]; -static char _fname_buf[FNAMEMAXSZ]; -static char _fcomment_buf[FCOMMENTMAXSZ]; - -struct gz -{ - char* HEADER; - int ID; - int CM; - int FLG; - int MTIME; - int XFL; - int OS; - int XLEN; - char* FLG_FEXTRA; - char* FLG_FNAME; - char* FLG_FCOMMENT; - int CRC16; - char* FLG_FHCRC; - char* block; - int CRC32; - size_t ISIZE; - size_t file_size; -}; - -static gz _gz; - -/* Read the input file *name, or stdin if name is NULL, into allocated memory. - Reallocate to larger buffers until the entire file is read in. Return a - pointer to the allocated data, or NULL if there was a memory allocation - failure. *len is the number of bytes of data read from the input file (even - if load() returns NULL). If the input file was empty or could not be opened - or read, *len is zero. */ -gz* loadgz(char* name) -{ - gz *r = &_gz; - char scratch[5]; - File *f = fopen(name); - int count; - int ID1; - int ID2; - int count1; - int count2; - int count3; - int count4; - int c; - int i; - char s[11]; - - r->file_size = f->size; - fread(s, 10, f); - - /* Verify header */ - r->HEADER = s; - ID1 = (s[0] & $FF); - ID2 = (s[1] & $FF); - r->ID = ((ID1 << 8) | ID2); - if($1f8b != r->ID) - { - fputs("bad header\n", ConsoleOut()); - return NULL; - } - - /* Verify Compression */ - r->CM = (r->HEADER[2] & $FF); - if(8 != r->CM) - { - fputs("NOT DEFLATE COMPRESSION\n", ConsoleOut()); - return NULL; - } - - /* Get specials specified in flag bits */ - r->FLG = (r->HEADER[3] & $FF); - - if(0 != (FEXTRA & r->FLG)) - { - fread(scratch, 4, f); - count1 = (scratch[0] & $FF); - count2 = (scratch[1] & $FF); - count3 = (scratch[2] & $FF); - count4 = (scratch[3] & $FF); - count = (count1 << 24) | (count2 << 16) | (count3 << 8) | count4; - if (0 > count) { - fputs("FEXTRA field needs to be a positive number of bytes in size\n", ConsoleOut()); - return NULL; - } - if (MAXGZSZ < count) { - fputs("we don't support FEXTRA fields greater than 1MB in size\n", ConsoleOut()); - return NULL; - } - r->FLG_FEXTRA = _extra_buf; - fread(_extra_buf, count, f); - } - - if(0 != (FNAME & r->FLG)) - { - r->FLG_FNAME = _fname_buf; - i = 0; - do - { - if (i == FNAMEMAXSZ) { - fputs("FNAME field size exceeds buffer size\n", ConsoleOut()); - return NULL; - } - c = fgetc(f); - if (c < 0) { - fputs("received a non-null terminated filename in the file\n", ConsoleOut()); - return NULL; - } - _fname_buf[i] = c; - i = i + 1; - } while(0 != c); - } - - if(0 != (FCOMMENT & r->FLG)) - { - r->FLG_FCOMMENT = _fcomment_buf; - i = 0; - do - { - if (i == FCOMMENTMAXSZ) { - fputs("FCOMMENTMAXSZ field size exceeds buffer size\n", ConsoleOut()); - return NULL; - } - c = fgetc(f); - if (c < 0) { - fputs("received a non-null terminated comment in the file\n", ConsoleOut()); - return NULL; - } - r->FLG_FCOMMENT[i] = c; - i = i + 1; - } while(0 != c); - } - - if(0 != (FHCRC & r->FLG)) - { - /* Not implemented */ - fputs("FHCRC is not implemented at this time\n", ConsoleOut()); - return NULL; - } - - if(NULL == r->FLG_FNAME) - { - count = strlen(name) - 3; - r->FLG_FNAME = _fname_buf; - i = 0; - while(i < count) - { - r->FLG_FNAME[i] = name[i]; - i = i + 1; - } - } - - r->block = _block_buf; - printf(r->file_size, f->pos, "hello %d %d\n"); - fread(r->block, r->file_size-f->pos, f); - r->ISIZE = count; - fclose(f); - return r; -} - -int ungz(char *fname) -{ - puffer* ret; - char* name; - char* buffer; - gz* in; - File *out; - - in = loadgz(name); - - if (in == NULL) - { - fputs("memory allocation failure\nDidn't read file\n", ConsoleOut()); - abort(); - } - - ret = puff(0, 0, in->block, in->ISIZE); - return 0; -}diff --git a/fs/ar/ungz.fs b/fs/ar/ungz.fs@@ -1,4 +0,0 @@ -?f<< /comp/c/lib.fs -cc<< /ar/ungz.c - -S" gz" findTypedef CType :exportdiff --git a/fs/tests/ar/all.fs b/fs/tests/ar/all.fs@@ -1 +1 @@ -f<< /tests/ar/ungz.fs +f<< /tests/ar/puff.fsdiff --git a/fs/tests/ar/puff.fs b/fs/tests/ar/puff.fs@@ -0,0 +1,5 @@ +?f<< /tests/harness.fs +?f<< /ar/puff.fs +testbegin +\ Testing ar/puff +testenddiff --git a/fs/tests/ar/ungz.fs b/fs/tests/ar/ungz.fs@@ -1,10 +0,0 @@ -?f<< /tests/harness.fs -?f<< /ar/ungz.fs -testbegin -\ Testing ar/ungz -\ a file with a GZ header returns nonzero -S" /tests/ar/hello.gz" loadgz dup # -gz FLG_FNAME dump -\ a file without one returns 0 -S" /tests/ar/all.fs" loadgz not # -testenddiff --git a/license/madler-puff.txt b/license/madler-puff.txt@@ -0,0 +1,20 @@ +Copyright (C) 2002-2013 Mark Adler, all rights reserved +version 2.3, 21 Jan 2013 + +This software is provided 'as-is', without any express or implied +warranty. In no event will the author be held liable for any damages +arising from the use of this software. + +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it +freely, subject to the following restrictions: + +1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. +2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. +3. This notice may not be removed or altered from any source distribution. + +Mark Adler madler@alumni.caltech.edudiff --git a/license/oriansj-ungz.txt b/license/oriansj-ungz.txt@@ -1,37 +0,0 @@ -/* Copyright (C) 2002-2013 Mark Adler, all rights reserved - * Copyright (C) 2021 Jeremiah Orians - * This file is part of mescc-tools-extra - * - * mescc-tools-extra is free software: you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, either version 3 of the License, or - * (at your option) any later version. - * - * mescc-tools-extra is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with mescc-tools-extra. If not, see <http://www.gnu.org/licenses/>. - */ - -/* puff.c - * Copyright (C) 2002-2013 Mark Adler, all rights reserved - * version 2.3, 21 Jan 2013 - * This software is provided 'as-is', without any express or implied - * warranty. In no event will the author be held liable for any damages - * arising from the use of this software. - * Permission is granted to anyone to use this software for any purpose, - * including commercial applications, and to alter it and redistribute it - * freely, subject to the following restrictions: - * 1. The origin of this software must not be misrepresented; you must not - * claim that you wrote the original software. If you use this software - * in a product, an acknowledgment in the product documentation would be - * appreciated but is not required. - * 2. Altered source versions must be plainly marked as such, and must not be - * misrepresented as being the original software. - * 3. This notice may not be removed or altered from any source distribution. - * Mark Adler madler@alumni.caltech.edu - */ -