From 83bf47c02f95a9956eb4f6a185014ab0fb62670b Mon Sep 17 00:00:00 2001 From: Glenn L McGrath Date: Wed, 20 Nov 2002 22:00:31 +0000 Subject: Speed and memory usage improvements from Laurence Adnerson --- archival/libunarchive/unzip.c | 177 +++++++++++++++++++++++------------------- 1 file changed, 95 insertions(+), 82 deletions(-) (limited to 'archival/libunarchive/unzip.c') diff --git a/archival/libunarchive/unzip.c b/archival/libunarchive/unzip.c index 7ebbd0ee7..d8d5b77b1 100644 --- a/archival/libunarchive/unzip.c +++ b/archival/libunarchive/unzip.c @@ -14,6 +14,8 @@ * General cleanup to better adhere to the style guide and make use of standard * busybox functions by Glenn McGrath * + * read_gz interface + associated hacking by Laurence Anderson + * * This program 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 2 of the License, or @@ -92,20 +94,15 @@ unsigned char *gunzip_in_buffer; /* gunzip_window size--must be a power of two, and * at least 32K for zip's deflate method */ static const int gunzip_wsize = 0x8000; -static int output_buffer_size = 0x8000; // gunzip_wsize initially static unsigned char *gunzip_window; static unsigned int *gunzip_crc_table; unsigned int gunzip_crc; -static unsigned char *output_buffer; -static unsigned int output_buffer_len; - /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */ #define BMAX 16 /* maximum bit length of any code (16 for explode) */ #define N_MAX 288 /* maximum number of codes in any set */ -static unsigned int gunzip_hufts; /* track memory usage */ static unsigned int gunzip_bb; /* bit buffer */ static unsigned char gunzip_bk; /* bits in bit buffer */ @@ -343,7 +340,6 @@ static int huft_build(unsigned int *b, const unsigned int n, /* allocate and link in new table */ q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t)); - gunzip_hufts += z + 1; /* track memory usage */ *t = q + 1; /* link to list for huft_free() */ *(t = &(q->v.t)) = NULL; u[h] = ++q; /* table starts after link */ @@ -395,36 +391,6 @@ static int huft_build(unsigned int *b, const unsigned int n, return y != 0 && g != 1; } -/* =========================================================================== - * Write the output gunzip_window gunzip_window[0..gunzip_outbuf_count-1] and update crc and gunzip_bytes_out. - * (Used for the decompressed data only.) - */ -static void flush_gunzip_window(void) -{ - int n; - - for (n = 0; n < gunzip_outbuf_count; n++) { - gunzip_crc = gunzip_crc_table[((int) gunzip_crc ^ (gunzip_window[n])) & 0xff] ^ (gunzip_crc >> 8); - } - - if (output_buffer_len == 0) { // Our buffer is empty -> straight memcpy - memcpy(output_buffer, gunzip_window, gunzip_outbuf_count); - output_buffer_len = gunzip_outbuf_count; - } else { // Bit more complicated, append to end of output_buffer, realloc as necessary - int newlen = output_buffer_len + gunzip_outbuf_count; - if (newlen > output_buffer_size) { - output_buffer = xrealloc(output_buffer, newlen); // Could free later, but as we now have the memory... - //printf("Using %d byte output buffer\n", newlen); - output_buffer_size = newlen; - } - memcpy(output_buffer + output_buffer_len, gunzip_window, gunzip_outbuf_count); - output_buffer_len += gunzip_outbuf_count; - } - - gunzip_bytes_out += gunzip_outbuf_count; - gunzip_outbuf_count = 0; -} - /* * inflate (decompress) the codes in a deflated (compressed) block. * Return an error code or zero if it all goes ok. @@ -468,7 +434,7 @@ static int inflate_codes(huft_t * my_tl, huft_t * my_td, const unsigned int my_b if ((e = (t = tl + ((unsigned) b & ml))->e) > 16) do { if (e == 99) { - return 1; + error_msg_and_die("inflate_codes error 1");; } b >>= t->b; k -= t->b; @@ -484,7 +450,7 @@ static int inflate_codes(huft_t * my_tl, huft_t * my_td, const unsigned int my_b gunzip_outbuf_count = (w); //flush_gunzip_window(); w = 0; - return -1; + return 1; // We have a block to read } } else { /* it's an EOB or a length */ @@ -504,7 +470,7 @@ static int inflate_codes(huft_t * my_tl, huft_t * my_td, const unsigned int my_b if ((e = (t = td + ((unsigned) b & md))->e) > 16) do { if (e == 99) - return 1; + error_msg_and_die("inflate_codes error 2");; b >>= t->b; k -= t->b; e -= 16; @@ -542,7 +508,7 @@ do_copy: do { else resumeCopy = 0; //flush_gunzip_window(); w = 0; - return -1; + return 1; } } while (n); resumeCopy = 0; @@ -563,7 +529,7 @@ do_copy: do { return 0; } -int inflate_stored(int my_n, int my_b_stored, int my_k_stored, int setup) +static int inflate_stored(int my_n, int my_b_stored, int my_k_stored, int setup) { static int n, b_stored, k_stored, w; if (setup) { @@ -584,7 +550,7 @@ int inflate_stored(int my_n, int my_b_stored, int my_k_stored, int setup) w = 0; b_stored >>= 8; k_stored -= 8; - return -1; // Means more stuff 2do + return 1; // We have a block } b_stored >>= 8; k_stored -= 8; @@ -866,51 +832,85 @@ static int inflate_block(int *e) } default: /* bad block type */ - error_msg("bad block type %d\n", t); - return 2; + error_msg_and_die("bad block type %d\n", t); + } +} + +static void calculate_gunzip_crc(void) +{ + int n; + for (n = 0; n < gunzip_outbuf_count; n++) { + gunzip_crc = gunzip_crc_table[((int) gunzip_crc ^ (gunzip_window[n])) & 0xff] ^ (gunzip_crc >> 8); + } + gunzip_bytes_out += gunzip_outbuf_count; +} + +static int inflate_get_next_window(void) +{ + static int needAnotherBlock = 1; + static int method = -1; // Method == -1 for stored, -2 for codes + static int e = 0; + + gunzip_outbuf_count = 0; + + while(1) { + int ret; + + if (needAnotherBlock) { + if(e) { calculate_gunzip_crc(); return 0; } // Last block + method = inflate_block(&e); + needAnotherBlock = 0; + } + + switch (method) { + case -1: ret = inflate_stored(0,0,0,0); + break; + case -2: ret = inflate_codes(0,0,0,0,0); + break; + default: error_msg_and_die("inflate error %d", method); + } + + if (ret == 1) { + calculate_gunzip_crc(); + return 1; // More data left + } else needAnotherBlock = 1; // End of that block } } /* - * decompress an inflated entry + * User functions * - * GLOBAL VARIABLES: gunzip_outbuf_count, bk, gunzip_bb, hufts, inptr + * read_gz, GZ_gzReadOpen, GZ_gzReadClose, inflate */ extern ssize_t read_gz(int fd, void *buf, size_t count) { - static int e = 0; /* last block flag */ - int r; /* result code */ - unsigned h = 0; /* maximum struct huft's malloc'ed */ - ssize_t written = count; - static char *output_buffer_ptr = 0; - - while (output_buffer_len == 0) { // We need more data - if (e) return 0; // No more data here! - gunzip_hufts = 0; - r = inflate_block(&e); - if (r == -1) { // Call inflate_stored while returning -1 - while(inflate_stored(0,0,0,0) == -1) flush_gunzip_window(); - } else if (r == -2) { // Call inflate_codes while returning -1 - while(inflate_codes(0,0,0,0,0) == -1) flush_gunzip_window(); - } else { - error_msg_and_die("inflate error %d", r); - return -1; - } - if (gunzip_hufts > h) { - h = gunzip_hufts; - } - if (e) { // Ok finished uncompressing, get any buffered uncompressed data - flush_gunzip_window(); - } - output_buffer_ptr = output_buffer; + static int morebytes = 0, finished = 0; + + if (morebytes) { + int bytesRead = morebytes > count ? count : morebytes; + memcpy(buf, gunzip_window + (gunzip_outbuf_count - morebytes), bytesRead); + morebytes -= bytesRead; + return bytesRead; + } else if (finished) { + return 0; + } else if (count >= 0x8000) { // We can decompress direcly to the buffer, 32k at a time + // Could decompress to larger buffer, but it must be a power of 2, and calculating that is probably more expensive than the benefit + unsigned char *old_gunzip_window = gunzip_window; // Save old window + gunzip_window = buf; + if (inflate_get_next_window() == 0) finished = 1; + gunzip_window = old_gunzip_window; // Restore old window + return gunzip_outbuf_count; + } else { // Oh well, need to split up the gunzip_window + int bytesRead; + if (inflate_get_next_window() == 0) finished = 1; + morebytes = gunzip_outbuf_count; + bytesRead = morebytes > count ? count : morebytes; + memcpy(buf, gunzip_window, bytesRead); + morebytes -= bytesRead; + return bytesRead; } - if (count > output_buffer_len) written = output_buffer_len; // We're only giving them as much as we have! - memcpy(buf, output_buffer_ptr, written); - output_buffer_ptr += written; - output_buffer_len -= written; - - return written; + } extern void GZ_gzReadOpen(int fd, void *unused, int nUnused) @@ -919,7 +919,6 @@ extern void GZ_gzReadOpen(int fd, void *unused, int nUnused) /* Allocate all global buffers (for DYN_ALLOC option) */ gunzip_window = xmalloc(gunzip_wsize); - output_buffer = xmalloc(gunzip_wsize); gunzip_outbuf_count = 0; gunzip_bytes_out = 0; gunzip_src_fd = fd; @@ -938,7 +937,6 @@ extern void GZ_gzReadClose(void) { /* Cleanup */ free(gunzip_window); - free(output_buffer); free(gunzip_crc_table); /* Store unused bytes in a global buffer so calling applets can access it */ @@ -953,11 +951,10 @@ extern void GZ_gzReadClose(void) } } -extern int inflate(int in, int out) +/*extern int inflate(int in, int out) // Useful for testing read_gz { char buf[8192]; ssize_t nread, nwrote; - ssize_t total = 0; GZ_gzReadOpen(in, 0, 0); while(1) { // Robbed from copyfd.c @@ -972,7 +969,23 @@ extern int inflate(int in, int out) perror_msg("write"); return -1; } - total += nwrote; + } + GZ_gzReadClose(); + return 0; +}*/ + +extern int inflate(int in, int out) +{ + ssize_t nwrote; + GZ_gzReadOpen(in, 0, 0); + while(1) { + int ret = inflate_get_next_window(); + nwrote = full_write(out, gunzip_window, gunzip_outbuf_count); + if (nwrote == -1) { + perror_msg("write"); + return -1; + } + if (ret == 0) break; } GZ_gzReadClose(); return 0; -- cgit v1.2.3