gzlib.c File Reference

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "misc/util/abc_global.h"
#include "gzguts.h"

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Macros
#define	LSEEK   lseek

Functions
local void gz_reset	OF ((gz_statep))
local gzFile gz_open	OF ((const char *, int, const char *))
local void	gz_reset (gz_statep state)
local gzFile	gz_open (const char *path, int fd, const char *mode)
gzFile ZEXPORT	gzopen (const char *path, const char *mode)
gzFile ZEXPORT	gzopen64 (const char *path, const char *mode)
gzFile ZEXPORT	gzdopen (int fd, const char *mode)
int ZEXPORT	gzbuffer (gzFile file, unsigned size)
int ZEXPORT	gzrewind (gzFile file)
z_off64_t ZEXPORT	gzseek64 (gzFile file, z_off64_t offset, int whence)
z_off_t ZEXPORT	gzseek (gzFile file, z_off_t offset, int whence)
z_off64_t ZEXPORT	gztell64 (gzFile file)
z_off_t ZEXPORT	gztell (gzFile file)
z_off64_t ZEXPORT	gzoffset64 (gzFile file)
z_off_t ZEXPORT	gzoffset (gzFile file)
int ZEXPORT	gzeof (gzFile file)
const char *ZEXPORT	gzerror (gzFile file, int *errnum)
void ZEXPORT	gzclearerr (gzFile file)
void ZLIB_INTERNAL	gz_error (gz_statep state, int err, const char *msg)
unsigned ZLIB_INTERNAL	gz_intmax ()

Macro Definition Documentation

LSEEK

#define LSEEK   lseek

Definition at line 18 of file gzlib.c.

Function Documentation

gz_error()

void ZLIB_INTERNAL gz_error	(	gz_statep	state,
		int	err,
		const char *	msg )

Definition at line 464 of file gzlib.c.

{
    /* free previously allocated message and clear */
    if (state->msg != NULL) {
        if (state->err != Z_MEM_ERROR)
            free(state->msg);
        state->msg = NULL;
    }
 
    /* set error code, and if no message, then done */
    state->err = err;
    if (msg == NULL)
        return;
 
    /* for an out of memory error, save as static string */
    if (err == Z_MEM_ERROR) {
        state->msg = (char *)msg;
        return;
    }
 
    /* construct error message with path */
    if ((state->msg = (char *)malloc(strlen(state->path) + strlen(msg) + 3)) == NULL) {
        state->err = Z_MEM_ERROR;
        state->msg = (char *)"out of memory";
        return;
    }
    strcpy(state->msg, state->path);
    strcat(state->msg, ": ");
    strcat(state->msg, msg);
    return;
}

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gz_intmax()

unsigned ZLIB_INTERNAL gz_intmax

(

)

Definition at line 501 of file gzlib.c.

{
    unsigned p, q;
 
    p = 1;
    do {
        q = p;
        p <<= 1;
        p++;
    } while (p > q);
    return q >> 1;
}

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gz_open()

local gzFile gz_open	(	const char *	path,
		int	fd,
		const char *	mode )

Definition at line 92 of file gzlib.c.

{
    gz_statep state;
 
    /* allocate gzFile structure to return */
    state = (gz_statep)malloc(sizeof(gz_state));
    if (state == NULL)
        return NULL;
    state->size = 0;            /* no buffers allocated yet */
    state->want = GZBUFSIZE;    /* requested buffer size */
    state->msg = NULL;          /* no error message yet */
 
    /* interpret mode */
    state->mode = GZ_NONE;
    state->level = Z_DEFAULT_COMPRESSION;
    state->strategy = Z_DEFAULT_STRATEGY;
    while (*mode) {
        if (*mode >= '0' && *mode <= '9')
            state->level = *mode - '0';
        else
            switch (*mode) {
            case 'r':
                state->mode = GZ_READ;
                break;
#ifndef NO_GZCOMPRESS
            case 'w':
                state->mode = GZ_WRITE;
                break;
            case 'a':
                state->mode = GZ_APPEND;
                break;
#endif
            case '+':       /* can't read and write at the same time */
                free(state);
                return NULL;
            case 'b':       /* ignore -- will request binary anyway */
                break;
            case 'f':
                state->strategy = Z_FILTERED;
                break;
            case 'h':
                state->strategy = Z_HUFFMAN_ONLY;
                break;
            case 'R':
                state->strategy = Z_RLE;
                break;
            case 'F':
                state->strategy = Z_FIXED;
            default:        /* could consider as an error, but just ignore */
                ;
            }
        mode++;
    }
 
    /* must provide an "r", "w", or "a" */
    if (state->mode == GZ_NONE) {
        free(state);
        return NULL;
    }
 
    /* save the path name for error messages */
    state->path = (char *)malloc(strlen(path) + 1);
    if (state->path == NULL) {
        free(state);
        return NULL;
    }
    strcpy(state->path, path);
 
    /* open the file with the appropriate mode (or just use fd) */
    state->fd = fd != -1 ? fd :
        open(path,
#ifdef O_LARGEFILE
            O_LARGEFILE |
#endif
#ifdef O_BINARY
            O_BINARY |
#endif
            (state->mode == GZ_READ ?
                O_RDONLY :
                (O_WRONLY | O_CREAT | (
                    state->mode == GZ_WRITE ?
                        O_TRUNC :
                        O_APPEND))),
            0666);
    if (state->fd == -1) {
        free(state->path);
        free(state);
        return NULL;
    }
    if (state->mode == GZ_APPEND)
        state->mode = GZ_WRITE;         /* simplify later checks */
 
    /* save the current position for rewinding (only if reading) */
    if (state->mode == GZ_READ) {
        state->start = LSEEK(state->fd, 0, SEEK_CUR);
        if (state->start == -1) state->start = 0;
    }
 
    /* initialize stream */
    gz_reset(state);
 
    /* return stream */
    return (gzFile)state;
}

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gz_reset()

local void gz_reset

(

gz_statep

state

)

Definition at line 77 of file gzlib.c.

{
    if (state->mode == GZ_READ) {   /* for reading ... */
        state->have = 0;            /* no output data available */
        state->eof = 0;             /* not at end of file */
        state->how = LOOK;          /* look for gzip header */
        state->direct = 1;          /* default for empty file */
    }
    state->seek = 0;                /* no seek request pending */
    gz_error(state, Z_OK, NULL);    /* clear error */
    state->pos = 0;                 /* no uncompressed data yet */
    state->strm.avail_in = 0;       /* no input data yet */
}

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gzbuffer()

int ZEXPORT gzbuffer	(	gzFile	file,
		unsigned	size )

Definition at line 224 of file gzlib.c.

{
    gz_statep state;
 
    /* get internal structure and check integrity */
    if (file == NULL)
        return -1;
    state = (gz_statep)file;
    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
        return -1;
 
    /* make sure we haven't already allocated memory */
    if (state->size != 0)
        return -1;
 
    /* check and set requested size */
    if (size == 0)
        return -1;
    state->want = size;
    return 0;
}

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gzclearerr()

void ZEXPORT gzclearerr

(

gzFile

file

)

Definition at line 441 of file gzlib.c.

{
    gz_statep state;
 
    /* get internal structure and check integrity */
    if (file == NULL)
        return;
    state = (gz_statep)file;
    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
        return;
 
    /* clear error and end-of-file */
    if (state->mode == GZ_READ)
        state->eof = 0;
    gz_error(state, Z_OK, NULL);
}

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gzdopen()

gzFile ZEXPORT gzdopen	(	int	fd,
		const char *	mode )

Definition at line 210 of file gzlib.c.

{
    char *path;         /* identifier for error messages */
    gzFile gz;
 
    if (fd == -1 || (path = (char *)malloc(7 + 3 * sizeof(int))) == NULL)
        return NULL;
    sprintf(path, "<fd:%d>", fd);   /* for debugging */
    gz = gz_open(path, fd, mode);
    free(path);
    return gz;
}

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gzeof()

int ZEXPORT gzeof

(

gzFile

file

)

Definition at line 406 of file gzlib.c.

{
    gz_statep state;
 
    /* get internal structure and check integrity */
    if (file == NULL)
        return 0;
    state = (gz_statep)file;
    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
        return 0;
 
    /* return end-of-file state */
    return state->mode == GZ_READ ?
        (state->eof && state->strm.avail_in == 0 && state->have == 0) : 0;
}

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gzerror()

const char *ZEXPORT gzerror	(	gzFile	file,
		int *	errnum )

Definition at line 423 of file gzlib.c.

{
    gz_statep state;
 
    /* get internal structure and check integrity */
    if (file == NULL)
        return NULL;
    state = (gz_statep)file;
    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
        return NULL;
 
    /* return error information */
    if (errnum != NULL)
        *errnum = state->err;
    return state->msg == NULL ? "" : state->msg;
}

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gzoffset()

z_off_t ZEXPORT gzoffset

(

gzFile

file

)

Definition at line 397 of file gzlib.c.

{
    z_off64_t ret;
 
    ret = gzoffset64(file);
    return ret == (z_off_t)ret ? (z_off_t)ret : -1;
}

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gzoffset64()

z_off64_t ZEXPORT gzoffset64

(

gzFile

file

)

Definition at line 375 of file gzlib.c.

{
    z_off64_t offset;
    gz_statep state;
 
    /* get internal structure and check integrity */
    if (file == NULL)
        return -1;
    state = (gz_statep)file;
    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
        return -1;
 
    /* compute and return effective offset in file */
    offset = LSEEK(state->fd, 0, SEEK_CUR);
    if (offset == -1)
        return -1;
    if (state->mode == GZ_READ)             /* reading */
        offset -= state->strm.avail_in;     /* don't count buffered input */
    return offset;
}

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gzopen()

gzFile ZEXPORT gzopen	(	const char *	path,
		const char *	mode )

Definition at line 198 of file gzlib.c.

{
    return gz_open(path, -1, mode);
}

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gzopen64()

gzFile ZEXPORT gzopen64	(	const char *	path,
		const char *	mode )

Definition at line 204 of file gzlib.c.

{
    return gz_open(path, -1, mode);
}

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gzrewind()

int ZEXPORT gzrewind

(

gzFile

file

)

Definition at line 247 of file gzlib.c.

{
    gz_statep state;
 
    /* get internal structure */
    if (file == NULL)
        return -1;
    state = (gz_statep)file;
 
    /* check that we're reading and that there's no error */
    if (state->mode != GZ_READ || state->err != Z_OK)
        return -1;
 
    /* back up and start over */
    if (LSEEK(state->fd, state->start, SEEK_SET) == -1)
        return -1;
    gz_reset(state);
    return 0;
}

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gzseek()

z_off_t ZEXPORT gzseek	(	gzFile	file,
		z_off_t	offset,
		int	whence )

Definition at line 341 of file gzlib.c.

{
    z_off64_t ret;
 
    ret = gzseek64(file, (z_off64_t)offset, whence);
    return ret == (z_off_t)ret ? (z_off_t)ret : -1;
}

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gzseek64()

z_off64_t ZEXPORT gzseek64	(	gzFile	file,
		z_off64_t	offset,
		int	whence )

Definition at line 268 of file gzlib.c.

{
    unsigned n;
    z_off64_t ret;
    gz_statep state;
 
    /* get internal structure and check integrity */
    if (file == NULL)
        return -1;
    state = (gz_statep)file;
    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
        return -1;
 
    /* check that there's no error */
    if (state->err != Z_OK)
        return -1;
 
    /* can only seek from start or relative to current position */
    if (whence != SEEK_SET && whence != SEEK_CUR)
        return -1;
 
    /* normalize offset to a SEEK_CUR specification */
    if (whence == SEEK_SET)
        offset -= state->pos;
    else if (state->seek)
        offset += state->skip;
    state->seek = 0;
 
    /* if within raw area while reading, just go there */
    if (state->mode == GZ_READ && state->how == COPY &&
        state->pos + offset >= state->raw) {
        ret = LSEEK(state->fd, offset - state->have, SEEK_CUR);
        if (ret == -1)
            return -1;
        state->have = 0;
        state->eof = 0;
        state->seek = 0;
        gz_error(state, Z_OK, NULL);
        state->strm.avail_in = 0;
        state->pos += offset;
        return state->pos;
    }
 
    /* calculate skip amount, rewinding if needed for back seek when reading */
    if (offset < 0) {
        if (state->mode != GZ_READ)         /* writing -- can't go backwards */
            return -1;
        offset += state->pos;
        if (offset < 0)                     /* before start of file! */
            return -1;
        if (gzrewind(file) == -1)           /* rewind, then skip to offset */
            return -1;
    }
 
    /* if reading, skip what's in output buffer (one less gzgetc() check) */
    if (state->mode == GZ_READ) {
        n = GT_OFF(state->have) || (z_off64_t)state->have > offset ?
            (unsigned)offset : state->have;
        state->have -= n;
        state->next += n;
        state->pos += n;
        offset -= n;
    }
 
    /* request skip (if not zero) */
    if (offset) {
        state->seek = 1;
        state->skip = offset;
    }
    return state->pos + offset;
}

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gztell()

z_off_t ZEXPORT gztell

(

gzFile

file

)

Definition at line 366 of file gzlib.c.

{
    z_off64_t ret;
 
    ret = gztell64(file);
    return ret == (z_off_t)ret ? (z_off_t)ret : -1;
}

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gztell64()

z_off64_t ZEXPORT gztell64

(

gzFile

file

)

Definition at line 350 of file gzlib.c.

{
    gz_statep state;
 
    /* get internal structure and check integrity */
    if (file == NULL)
        return -1;
    state = (gz_statep)file;
    if (state->mode != GZ_READ && state->mode != GZ_WRITE)
        return -1;
 
    /* return position */
    return state->pos + (state->seek ? state->skip : 0);
}

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OF() [1/2]

local gzFile gz_open OF

(

(const char *, int, const char *)

)

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OF() [2/2]

local void gz_reset OF

(

(gz_statep)

)

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