/*
* 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;
}
