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authorErlang/OTP <[email protected]>2009-11-20 14:54:40 +0000
committerErlang/OTP <[email protected]>2009-11-20 14:54:40 +0000
commit84adefa331c4159d432d22840663c38f155cd4c1 (patch)
treebff9a9c66adda4df2106dfd0e5c053ab182a12bd /erts/emulator/drivers/common/gzio.c
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The R13B03 release.OTP_R13B03
Diffstat (limited to 'erts/emulator/drivers/common/gzio.c')
-rw-r--r--erts/emulator/drivers/common/gzio.c822
1 files changed, 822 insertions, 0 deletions
diff --git a/erts/emulator/drivers/common/gzio.c b/erts/emulator/drivers/common/gzio.c
new file mode 100644
index 0000000000..801bc61d4d
--- /dev/null
+++ b/erts/emulator/drivers/common/gzio.c
@@ -0,0 +1,822 @@
+/*
+ * Original version by Jean-loup Gailly. Modified for use by the
+ * Erlang run-time system and efile_driver; names of all external
+ * functions changed to avoid conflicts with the official gzio.c file.
+ *
+ * gzio.c -- IO on .gz files
+ * Copyright (C) 1995-1996 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+/* %ExternalCopyright% */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+#include <stdio.h>
+#include <errno.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <ctype.h>
+#include "erl_driver.h"
+#include "sys.h"
+
+#ifdef VXWORKS
+/* pull in FOPEN from zutil.h instead */
+#undef F_OPEN
+#endif
+
+#ifdef __WIN32__
+#define HAVE_CONFLICTING_FREAD_DECLARATION
+#endif
+
+#ifdef STDC
+# define zstrerror(errnum) strerror(errnum)
+#else
+# define zstrerror(errnum) ""
+#endif
+
+#include "gzio_zutil.h"
+#include "erl_zlib.h"
+#include "gzio.h"
+
+/********struct internal_state {int dummy;}; / * for buggy compilers */
+
+#define Z_BUFSIZE 4096
+
+#define ALLOC(size) driver_alloc(size)
+#define TRYFREE(p) {if (p) driver_free(p);}
+
+static int gz_magic[2] = {0x1f, 0x8b}; /* gzip magic header */
+
+/* gzip flag byte */
+#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
+#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */
+#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
+#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
+#define COMMENT 0x10 /* bit 4 set: file comment present */
+#define RESERVED 0xE0 /* bits 5..7: reserved */
+
+typedef struct gz_stream {
+ z_stream stream;
+ int z_err; /* error code for last stream operation */
+ int z_eof; /* set if end of input file */
+#ifdef UNIX
+ int file; /* .gz file descriptor */
+#else
+ FILE *file; /* .gz file */
+#endif
+ Byte *inbuf; /* input buffer */
+ Byte *outbuf; /* output buffer */
+ uLong crc; /* crc32 of uncompressed data */
+ char *msg; /* error message */
+ char *path; /* path name for debugging only */
+ int transparent; /* 1 if input file is not a .gz file */
+ char mode; /* 'w' or 'r' */
+ int position; /* Position (for seek) */
+ int (*destroy)OF((struct gz_stream*)); /* Function to destroy
+ * this structure. */
+} gz_stream;
+
+local gzFile gz_open OF((const char *path, const char *mode));
+local int get_byte OF((gz_stream *s));
+local void check_header OF((gz_stream *s));
+local int destroy OF((gz_stream *s));
+local uLong getLong OF((gz_stream *s));
+
+#ifdef UNIX
+/*
+ * In Solaris 8 and earlier, fopen() and its friends cannot handle
+ * file descriptors larger than 255. Therefore, we use read()/write()
+ * on all Unix systems.
+ */
+# define ERTS_GZWRITE(File, Buf, Count) write((File), (Buf), (Count))
+# define ERTS_GZREAD(File, Buf, Count) read((File), (Buf), (Count))
+#else
+/*
+ * On all other operating systems, using fopen(), fread()/fwrite(), since
+ * there is not guaranteed to exist any read()/write() (not part of
+ * ANSI/ISO-C).
+ */
+# define ERTS_GZWRITE(File, Buf, Count) fwrite((Buf), 1, (Count), (File))
+# define ERTS_GZREAD(File, Buf, Count) fread((Buf), 1, (Count), (File))
+#endif
+
+/* ===========================================================================
+ Opens a gzip (.gz) file for reading or writing. The mode parameter
+ is as in fopen ("rb" or "wb"). The file is given either by file descriptor
+ or path name (if fd == -1).
+ gz_open return NULL if the file could not be opened or if there was
+ insufficient memory to allocate the (de)compression state; errno
+ can be checked to distinguish the two cases (if errno is zero, the
+ zlib error is Z_MEM_ERROR).
+*/
+local gzFile gz_open (path, mode)
+ const char *path;
+ const char *mode;
+{
+ int err;
+ int level = Z_DEFAULT_COMPRESSION; /* compression level */
+ char *p = (char*)mode;
+ gz_stream *s;
+ char fmode[80]; /* copy of mode, without the compression level */
+ char *m = fmode;
+
+ if (!path || !mode) return Z_NULL;
+
+ s = (gz_stream *)ALLOC(sizeof(gz_stream));
+ if (!s) return Z_NULL;
+
+ erl_zlib_alloc_init(&s->stream);
+ s->stream.next_in = s->inbuf = Z_NULL;
+ s->stream.next_out = s->outbuf = Z_NULL;
+ s->stream.avail_in = s->stream.avail_out = 0;
+#ifdef UNIX
+ s->file = -1;
+#else
+ s->file = NULL;
+#endif
+ s->z_err = Z_OK;
+ s->z_eof = 0;
+ s->crc = crc32(0L, Z_NULL, 0);
+ s->msg = NULL;
+ s->transparent = 0;
+ s->position = 0;
+ s->destroy = destroy;
+
+ s->path = (char*)ALLOC(strlen(path)+1);
+ if (s->path == NULL) {
+ return s->destroy(s), (gzFile)Z_NULL;
+ }
+ strcpy(s->path, path); /* do this early for debugging */
+
+ s->mode = '\0';
+ do {
+ if (*p == 'r')
+ s->mode = 'r';
+ if (*p == 'w' || *p == 'a')
+ s->mode = 'w';
+ if (isdigit((int)*p)) {
+ level = *p - '0';
+ } else {
+ *m++ = *p; /* Copy the mode */
+ }
+ } while (*p++ && m < fmode + sizeof(fmode) - 1);
+ *m = '\0';
+ if (s->mode == '\0')
+ return s->destroy(s), (gzFile)Z_NULL;
+
+ if (s->mode == 'w') {
+ err = deflateInit2(&(s->stream), level,
+ Z_DEFLATED, MAX_WBITS+16, DEF_MEM_LEVEL, 0);
+ /* windowBits is passed < 0 to suppress zlib header */
+
+ s->stream.next_out = s->outbuf = (Byte*)ALLOC(Z_BUFSIZE);
+
+ if (err != Z_OK || s->outbuf == Z_NULL) {
+ return s->destroy(s), (gzFile)Z_NULL;
+ }
+ } else {
+ /*
+ * It is tempting to use the built-in support in zlib
+ * for handling GZIP headers, but unfortunately it
+ * cannot handle multiple GZIP headers (which occur when
+ * several GZIP files have been concatenated).
+ */
+
+ err = inflateInit2(&(s->stream), -MAX_WBITS);
+ s->stream.next_in = s->inbuf = (Byte*)ALLOC(Z_BUFSIZE);
+
+ if (err != Z_OK || s->inbuf == Z_NULL) {
+ return s->destroy(s), (gzFile)Z_NULL;
+ }
+ }
+ s->stream.avail_out = Z_BUFSIZE;
+
+ errno = 0;
+#ifdef UNIX
+ if (s->mode == 'r') {
+ s->file = open(path, O_RDONLY);
+ } else {
+ s->file = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+ }
+ if (s->file == -1) {
+ return s->destroy(s), (gzFile)Z_NULL;
+ }
+#else
+ s->file = F_OPEN(path, fmode);
+ if (s->file == NULL) {
+ return s->destroy(s), (gzFile)Z_NULL;
+ }
+#endif
+ if (s->mode == 'r') {
+ check_header(s); /* skip the .gz header */
+ }
+ return (gzFile)s;
+}
+
+/* ===========================================================================
+ Rewind a gzfile back to the beginning.
+*/
+
+local int gz_rewind (gz_stream *s)
+{
+ TRYFREE(s->msg);
+
+#ifdef UNIX
+ lseek(s->file, 0L, SEEK_SET);
+#else
+ fseek(s->file, 0L, SEEK_SET);
+#endif
+ inflateReset(&(s->stream));
+ s->stream.next_in = Z_NULL;
+ s->stream.next_out = Z_NULL;
+ s->stream.avail_in = s->stream.avail_out = 0;
+ s->z_err = Z_OK;
+ s->z_eof = 0;
+ s->crc = crc32(0L, Z_NULL, 0);
+ s->msg = NULL;
+ s->position = 0;
+ s->stream.next_in = s->inbuf;
+
+ s->stream.avail_out = Z_BUFSIZE;
+
+ check_header(s); /* skip the .gz header */
+ return 1;
+}
+
+/* ===========================================================================
+ Opens a gzip (.gz) file for reading or writing.
+*/
+gzFile erts_gzopen (path, mode)
+ const char *path;
+ const char *mode;
+{
+ return gz_open (path, mode);
+}
+
+
+/* ===========================================================================
+ Read a byte from a gz_stream; update next_in and avail_in. Return EOF
+ for end of file.
+ IN assertion: the stream s has been sucessfully opened for reading.
+*/
+local int get_byte(s)
+ gz_stream *s;
+{
+ if (s->z_eof) return EOF;
+ if (s->stream.avail_in == 0) {
+#ifdef UNIX
+ size_t res;
+ errno = 0;
+ res = ERTS_GZREAD(s->file, s->inbuf, Z_BUFSIZE);
+ if (res == 0) {
+ s->stream.avail_in = 0;
+ s->z_eof = 1;
+ return EOF;
+ } else if (res < 0) {
+ s->stream.avail_in = 0;
+ s->z_eof = 1;
+ s->z_err = Z_ERRNO;
+ return EOF;
+ } else {
+ s->stream.avail_in = (uInt) res;
+ }
+#else
+ errno = 0;
+ s->stream.avail_in = ERTS_GZREAD(s->file, s->inbuf, Z_BUFSIZE);
+ if (s->stream.avail_in == 0) {
+ s->z_eof = 1;
+ if (s->file && ferror(s->file))
+ s->z_err = Z_ERRNO;
+ return EOF;
+ }
+#endif
+ s->stream.next_in = s->inbuf;
+ }
+ s->stream.avail_in--;
+ return *(s->stream.next_in)++;
+}
+
+/* ===========================================================================
+ Check the gzip header of a gz_stream opened for reading. Set the stream
+ mode to transparent if the gzip magic header is not present; set s->err
+ to Z_DATA_ERROR if the magic header is present but the rest of the header
+ is incorrect.
+ IN assertion: the stream s has already been created sucessfully;
+ s->stream.avail_in is zero for the first time, but may be non-zero
+ for concatenated .gz files.
+*/
+local void check_header(s)
+ gz_stream *s;
+{
+ int method; /* method byte */
+ int flags; /* flags byte */
+ uInt len;
+ int c;
+
+ /* Check the gzip magic header */
+ for (len = 0; len < 2; len++) {
+ c = get_byte(s);
+ if (c != gz_magic[len]) {
+ if (len != 0) s->stream.avail_in++, s->stream.next_in--;
+ if (c != EOF) {
+ s->stream.avail_in++, s->stream.next_in--;
+ s->transparent = 1;
+ }
+ s->z_err = s->stream.avail_in != 0 ? Z_OK : Z_STREAM_END;
+ return;
+ }
+ }
+ method = get_byte(s);
+ flags = get_byte(s);
+ if (method != Z_DEFLATED || (flags & RESERVED) != 0) {
+ s->z_err = Z_DATA_ERROR;
+ return;
+ }
+
+ /* Discard time, xflags and OS code: */
+ for (len = 0; len < 6; len++) (void)get_byte(s);
+
+ if ((flags & EXTRA_FIELD) != 0) { /* skip the extra field */
+ len = (uInt)get_byte(s);
+ len += ((uInt)get_byte(s))<<8;
+ /* len is garbage if EOF but the loop below will quit anyway */
+ while (len-- != 0 && get_byte(s) != EOF) ;
+ }
+ if ((flags & ORIG_NAME) != 0) { /* skip the original file name */
+ while ((c = get_byte(s)) != 0 && c != EOF) ;
+ }
+ if ((flags & COMMENT) != 0) { /* skip the .gz file comment */
+ while ((c = get_byte(s)) != 0 && c != EOF) ;
+ }
+ if ((flags & HEAD_CRC) != 0) { /* skip the header crc */
+ for (len = 0; len < 2; len++) (void)get_byte(s);
+ }
+ s->z_err = s->z_eof ? Z_DATA_ERROR : Z_OK;
+}
+
+ /* ===========================================================================
+ * Cleanup then free the given gz_stream. Return a zlib error code.
+ Try freeing in the reverse order of allocations.
+ */
+local int destroy (s)
+ gz_stream *s;
+{
+ int err = Z_OK;
+
+ if (!s) return Z_STREAM_ERROR;
+
+ TRYFREE(s->msg);
+
+ if (s->stream.state != NULL) {
+ if (s->mode == 'w') {
+ err = deflateEnd(&(s->stream));
+ } else if (s->mode == 'r') {
+ err = inflateEnd(&(s->stream));
+ }
+ }
+#ifdef UNIX
+ if (s->file != -1 && close(s->file)) {
+ err = Z_ERRNO;
+ }
+#else
+ if (s->file != NULL && fclose(s->file)) {
+ err = Z_ERRNO;
+ }
+#endif
+ if (s->z_err < 0) err = s->z_err;
+
+ TRYFREE(s->inbuf);
+ TRYFREE(s->outbuf);
+ TRYFREE(s->path);
+ TRYFREE(s);
+ return err;
+}
+
+/* ===========================================================================
+ Reads the given number of uncompressed bytes from the compressed file.
+ gzread returns the number of bytes actually read (0 for end of file).
+*/
+int
+erts_gzread(gzFile file, voidp buf, unsigned len)
+{
+ gz_stream *s = (gz_stream*)file;
+ Bytef *start = buf; /* starting point for crc computation */
+ Byte *next_out; /* == stream.next_out but not forced far (for MSDOS) */
+
+ if (s == NULL || s->mode != 'r') return Z_STREAM_ERROR;
+
+ if (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO) return -1;
+ if (s->z_err == Z_STREAM_END) return 0; /* EOF */
+
+ s->stream.next_out = next_out = buf;
+ s->stream.avail_out = len;
+
+ while (s->stream.avail_out != 0) {
+
+ if (s->transparent) {
+ /* Copy first the lookahead bytes: */
+ uInt n = s->stream.avail_in;
+ if (n > s->stream.avail_out) n = s->stream.avail_out;
+ if (n > 0) {
+ zmemcpy(s->stream.next_out, s->stream.next_in, n);
+ next_out += n;
+ s->stream.next_out = next_out;
+ s->stream.next_in += n;
+ s->stream.avail_out -= n;
+ s->stream.avail_in -= n;
+ }
+ if (s->stream.avail_out > 0) {
+ s->stream.avail_out -= ERTS_GZREAD(s->file, next_out,
+ s->stream.avail_out);
+ }
+ len -= s->stream.avail_out;
+ s->stream.total_in += (uLong)len;
+ s->stream.total_out += (uLong)len;
+ if (len == 0) s->z_eof = 1;
+ s->position += (int)len;
+ return (int)len;
+ }
+ if (s->stream.avail_in == 0 && !s->z_eof) {
+#ifdef UNIX
+ size_t res;
+ errno = 0;
+ res = ERTS_GZREAD(s->file, s->inbuf, Z_BUFSIZE);
+ if (res == 0) {
+ s->stream.avail_in = 0;
+ s->z_eof = 1;
+ return EOF;
+ } else if (res < 0) {
+ s->stream.avail_in = 0;
+ s->z_eof = 1;
+ s->z_err = Z_ERRNO;
+ return EOF;
+ } else {
+ s->stream.avail_in = (uInt) res;
+ }
+#else
+ errno = 0;
+ s->stream.avail_in = ERTS_GZREAD(s->file, s->inbuf, Z_BUFSIZE);
+ if (s->stream.avail_in == 0) {
+ s->z_eof = 1;
+ if (s->file && ferror(s->file)) {
+ s->z_err = Z_ERRNO;
+ break;
+ }
+ }
+#endif
+ s->stream.next_in = s->inbuf;
+ }
+ s->z_err = inflate(&(s->stream), Z_NO_FLUSH);
+
+ if (s->z_err == Z_STREAM_END) {
+ /* Check CRC and original size */
+ s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
+ start = s->stream.next_out;
+
+ if (getLong(s) != s->crc) {
+ s->z_err = Z_DATA_ERROR;
+ } else {
+ (void)getLong(s);
+ /* The uncompressed length returned by above getlong() may
+ * be different from s->stream.total_out) in case of
+ * concatenated .gz files. Check for such files:
+ */
+ check_header(s);
+ if (s->z_err == Z_OK) {
+ uLong total_in = s->stream.total_in;
+ uLong total_out = s->stream.total_out;
+
+ inflateReset(&(s->stream));
+ s->stream.total_in = total_in;
+ s->stream.total_out = total_out;
+ s->crc = crc32(0L, Z_NULL, 0);
+ }
+ }
+ }
+ if (s->z_err != Z_OK || s->z_eof) break;
+ }
+ s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
+
+ s->position += (int)(len - s->stream.avail_out);
+
+ return (int)(len - s->stream.avail_out);
+}
+
+/* ===========================================================================
+ Writes the given number of uncompressed bytes into the compressed file.
+ gzwrite returns the number of bytes actually written (0 in case of error).
+*/
+int
+erts_gzwrite(gzFile file, voidp buf, unsigned len)
+{
+ gz_stream *s = (gz_stream*)file;
+
+ if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
+
+ s->stream.next_in = buf;
+ s->stream.avail_in = len;
+
+ while (s->stream.avail_in != 0) {
+
+ if (s->stream.avail_out == 0) {
+
+ s->stream.next_out = s->outbuf;
+ if (ERTS_GZWRITE(s->file, s->outbuf, Z_BUFSIZE) != Z_BUFSIZE) {
+ s->z_err = Z_ERRNO;
+ break;
+ }
+ s->stream.avail_out = Z_BUFSIZE;
+ }
+ s->z_err = deflate(&(s->stream), Z_NO_FLUSH);
+ if (s->z_err != Z_OK) break;
+ }
+ s->position += (int)(len - s->stream.avail_in);
+ return (int)(len - s->stream.avail_in);
+}
+
+/*
+ * For use by Erlang file driver.
+ *
+ * XXX Limitations:
+ * - SEEK_END is not allowed (length of file is not known).
+ * - When writing, only forward seek is supported.
+ */
+
+int
+erts_gzseek(gzFile file, int offset, int whence)
+{
+ int pos;
+ gz_stream* s = (gz_stream *) file;
+
+ if (s == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+ if (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO) {
+ errno = EIO;
+ return -1;
+ }
+
+ switch (whence) {
+ case SEEK_SET: pos = offset; break;
+ case SEEK_CUR: pos = s->position+offset; break;
+ case SEEK_END:
+ default:
+ errno = EINVAL; return -1;
+ }
+
+ if (pos == s->position) {
+ return pos;
+ }
+
+ if (pos < s->position) {
+ if (s->mode == 'w') {
+ errno = EINVAL;
+ return -1;
+ }
+ gz_rewind(s);
+ }
+
+ while (s->position < pos) {
+ char buf[512];
+ int n;
+
+ n = pos - s->position;
+ if (n > sizeof(buf))
+ n = sizeof(buf);
+
+ if (s->mode == 'r') {
+ erts_gzread(file, buf, n);
+ } else {
+ memset(buf, '\0', n);
+ erts_gzwrite(file, buf, n);
+ }
+ }
+
+ return s->position;
+}
+
+/* ===========================================================================
+ Flushes all pending output into the compressed file. The parameter
+ flush is as in the deflate() function.
+ gzflush should be called only when strictly necessary because it can
+ degrade compression.
+*/
+int
+erts_gzflush(gzFile file, int flush)
+{
+ uInt len;
+ int done = 0;
+ gz_stream *s = (gz_stream*)file;
+
+ if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
+
+ s->stream.avail_in = 0; /* should be zero already anyway */
+
+ for (;;) {
+ len = Z_BUFSIZE - s->stream.avail_out;
+
+ if (len != 0) {
+ if ((uInt)ERTS_GZWRITE(s->file, s->outbuf, len) != len) {
+ s->z_err = Z_ERRNO;
+ return Z_ERRNO;
+ }
+ s->stream.next_out = s->outbuf;
+ s->stream.avail_out = Z_BUFSIZE;
+ }
+ if (done) break;
+ s->z_err = deflate(&(s->stream), flush);
+
+ /* deflate has finished flushing only when it hasn't used up
+ * all the available space in the output buffer:
+ */
+ done = (s->stream.avail_out != 0 || s->z_err == Z_STREAM_END);
+
+ if (s->z_err != Z_OK && s->z_err != Z_STREAM_END) break;
+ }
+#ifndef UNIX
+ fflush(s->file);
+#endif
+ return s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
+}
+
+/* ===========================================================================
+ Reads a long in LSB order from the given gz_stream. Sets
+*/
+local uLong getLong (s)
+ gz_stream *s;
+{
+ uLong x = (uLong)get_byte(s);
+ int c;
+
+ x += ((uLong)get_byte(s))<<8;
+ x += ((uLong)get_byte(s))<<16;
+ c = get_byte(s);
+ if (c == EOF) s->z_err = Z_DATA_ERROR;
+ x += ((uLong)c)<<24;
+ return x;
+}
+
+/* ===========================================================================
+ Flushes all pending output if necessary, closes the compressed file
+ and deallocates all the (de)compression state.
+*/
+int
+erts_gzclose(gzFile file)
+{
+ int err;
+ gz_stream *s = (gz_stream*)file;
+
+ if (s == NULL) return Z_STREAM_ERROR;
+
+ if (s->mode == 'w') {
+ err = erts_gzflush (file, Z_FINISH);
+ if (err != Z_OK) return s->destroy(file);
+ }
+ return s->destroy(file);
+}
+
+
+/* ===========================================================================
+ Uncompresses the buffer given and returns a pointer to a binary.
+ If the buffer was not compressed with gzip, the buffer contents
+ will be copied unchanged into the binary.
+
+ If a `gzip' header was found, but there were subsequent errors,
+ a NULL pointer is returned.
+*/
+
+ErlDrvBinary*
+erts_gzinflate_buffer(char* start, uLong size)
+{
+ ErlDrvBinary* bin;
+ ErlDrvBinary* bin2;
+ z_stream zstr;
+ unsigned char* bptr;
+
+ /*
+ * Check for the magic bytes beginning a GZIP header.
+ */
+ bptr = (unsigned char *) start;
+ if (size < 2 || bptr[0] != gz_magic[0] || bptr[1] != gz_magic[1]) {
+ /* No GZIP header -- just copy the data into a new binary */
+ if ((bin = driver_alloc_binary(size)) == NULL) {
+ return NULL;
+ }
+ memcpy(bin->orig_bytes, start, size);
+ return bin;
+ }
+
+ /*
+ * The magic bytes for a GZIP header are there. Now try to decompress.
+ * It is an error if the GZIP header is not correct.
+ */
+
+ zstr.next_in = (unsigned char*) start;
+ zstr.avail_in = size;
+ erl_zlib_alloc_init(&zstr);
+ size *= 2;
+ if ((bin = driver_alloc_binary(size)) == NULL) {
+ return NULL;
+ }
+ if (inflateInit2(&zstr, 15+16) != Z_OK) { /* Decode GZIP format */
+ driver_free(bin);
+ return NULL;
+ }
+ for (;;) {
+ int status;
+
+ zstr.next_out = (unsigned char *) bin->orig_bytes + zstr.total_out;
+ zstr.avail_out = size - zstr.total_out;
+ status = inflate(&zstr, Z_NO_FLUSH);
+ if (status == Z_OK) {
+ size *= 2;
+ if ((bin2 = driver_realloc_binary(bin, size)) == NULL) {
+ error:
+ driver_free_binary(bin);
+ inflateEnd(&zstr);
+ return NULL;
+ }
+ bin = bin2;
+ } else if (status == Z_STREAM_END) {
+ if ((bin2 = driver_realloc_binary(bin, zstr.total_out)) == NULL) {
+ goto error;
+ }
+ inflateEnd(&zstr);
+ return bin2;
+ } else {
+ goto error;
+ }
+ }
+}
+
+/* ===========================================================================
+ Compresses the buffer given and returns a pointer to a binary.
+ A NULL pointer is returned if any error occurs.
+ Writes a gzip header as well.
+*/
+
+#define GZIP_HD_SIZE 10
+#define GZIP_TL_SIZE 8
+
+#define GZIP_X_SIZE (GZIP_HD_SIZE+GZIP_TL_SIZE)
+
+ErlDrvBinary*
+erts_gzdeflate_buffer(char* start, uLong size)
+{
+ z_stream c_stream; /* compression stream */
+ ErlDrvBinary* bin;
+ ErlDrvBinary* bin2;
+ uLong crc; /* crc32 of uncompressed data */
+ uLong szIn;
+ Byte* ptr;
+ int comprLen = size + (size/1000) + 1 + 12; /* see zlib.h */
+
+ crc = crc32(0L, Z_NULL, 0);
+ erl_zlib_alloc_init(&c_stream);
+
+ if (deflateInit2(&c_stream, Z_DEFAULT_COMPRESSION,
+ Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL, 0) != Z_OK)
+ return NULL;
+
+ if ((bin = driver_alloc_binary(comprLen+GZIP_X_SIZE)) == NULL)
+ return NULL;
+ sprintf(bin->orig_bytes, "%c%c%c%c%c%c%c%c%c%c", gz_magic[0], gz_magic[1],
+ Z_DEFLATED, 0 /*flags*/, 0,0,0,0 /*time*/, 0 /*xflags*/, OS_CODE);
+
+ c_stream.next_out = ((Byte*) bin->orig_bytes)+GZIP_HD_SIZE;
+ c_stream.avail_out = (uInt) bin->orig_size - GZIP_HD_SIZE;
+ c_stream.next_in = (Byte*) start;
+ c_stream.avail_in = (uInt) size;
+
+ if (deflate(&c_stream, Z_FINISH) != Z_STREAM_END) {
+ driver_free_binary(bin);
+ return NULL;
+ }
+ crc = crc32(crc, (unsigned char*)start, size);
+ ptr = c_stream.next_out;
+ szIn = c_stream.total_in;
+
+ *ptr++ = (crc & 0xff); crc >>= 8;
+ *ptr++ = (crc & 0xff); crc >>= 8;
+ *ptr++ = (crc & 0xff); crc >>= 8;
+ *ptr++ = (crc & 0xff); crc >>= 8;
+
+ *ptr++ = (szIn & 0xff); szIn >>= 8;
+ *ptr++ = (szIn & 0xff); szIn >>= 8;
+ *ptr++ = (szIn & 0xff); szIn >>= 8;
+ *ptr++ = (szIn & 0xff); szIn >>= 8;
+
+ if (deflateEnd(&c_stream) != Z_OK) {
+ driver_free_binary(bin);
+ return NULL;
+ }
+ size = ptr - (Byte*)bin->orig_bytes;
+
+ if ((bin2 = driver_realloc_binary(bin, size)) == NULL)
+ driver_free_binary(bin);
+ return bin2;
+}
+