gzwrite.c File Reference

#include "gzguts.h"

Include dependency graph for gzwrite.c:

Functions
static int gz_init	OF ((gz_statep))
static int gz_comp	OF ((gz_statep, int))
static int gz_zero	OF ((gz_statep, z_off64_t))
static int	gz_init (gz_statep state)
static int	gz_comp (gz_statep state, int flush)
static int	gz_zero (gz_statep state, z_off64_t len)
int ZEXPORT	gzwrite (gzFile file, voidpc buf, unsigned len)
int ZEXPORT	gzputc (gzFile file, int c)
int ZEXPORT	gzputs (gzFile file, const char *str)
int ZEXPORTVA	gzprintf (gzFile file, const char *format, int a1, int a2, int a3, int a4, int a5, int a6, int a7, int a8, int a9, int a10, int a11, int a12, int a13, int a14, int a15, int a16, int a17, int a18, int a19, int a20)
int ZEXPORT	gzflush (gzFile file, int flush)
int ZEXPORT	gzsetparams (gzFile file, int level, int strategy)
int ZEXPORT	gzclose_w (gzFile file)

Function Documentation

static int gz_init OF ( (gz_statep)  )

static

static int gz_comp OF ( (gz_statep, int)  )

static

static int gz_zero OF ( (gz_statep, z_off64_t)  )

static

static int gz_init ( gz_statep  state )

static

{
    int ret;
    z_streamp strm = &(state->strm);

    /* allocate input buffer */
    state->in = (unsigned char *)malloc(state->want);
    if (state->in == NULL) {
        gz_error(state, Z_MEM_ERROR, "out of memory");
        return -1;
    }

    /* only need output buffer and deflate state if compressing */
    if (!state->direct) {
        /* allocate output buffer */
        state->out = (unsigned char *)malloc(state->want);
        if (state->out == NULL) {
            free(state->in);
            gz_error(state, Z_MEM_ERROR, "out of memory");
            return -1;
        }

        /* allocate deflate memory, set up for gzip compression */
        strm->zalloc = Z_NULL;
        strm->zfree = Z_NULL;
        strm->opaque = Z_NULL;
        ret = deflateInit2(strm, state->level, Z_DEFLATED,
                           MAX_WBITS + 16, DEF_MEM_LEVEL, state->strategy);
        if (ret != Z_OK) {
            free(state->out);
            free(state->in);
            gz_error(state, Z_MEM_ERROR, "out of memory");
            return -1;
        }
    }

    /* mark state as initialized */
    state->size = state->want;

    /* initialize write buffer if compressing */
    if (!state->direct) {
        strm->avail_out = state->size;
        strm->next_out = state->out;
        state->x.next = strm->next_out;
    }
    return 0;
}

static int gz_comp ( gz_statep  state, int  flush  )

static

{
    int ret, got;
    unsigned have;
    z_streamp strm = &(state->strm);

    /* allocate memory if this is the first time through */
    if (state->size == 0 && gz_init(state) == -1)
        return -1;

    /* write directly if requested */
    if (state->direct) {
        got = write(state->fd, strm->next_in, strm->avail_in);
        if (got < 0 || (unsigned)got != strm->avail_in) {
            gz_error(state, Z_ERRNO, zstrerror());
            return -1;
        }
        strm->avail_in = 0;
        return 0;
    }

    /* run deflate() on provided input until it produces no more output */
    ret = Z_OK;
    do {
        /* write out current buffer contents if full, or if flushing, but if
           doing Z_FINISH then don't write until we get to Z_STREAM_END */
        if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
            (flush != Z_FINISH || ret == Z_STREAM_END))) {
            have = (unsigned)(strm->next_out - state->x.next);
            if (have && ((got = write(state->fd, state->x.next, have)) < 0 ||
                         (unsigned)got != have)) {
                gz_error(state, Z_ERRNO, zstrerror());
                return -1;
            }
            if (strm->avail_out == 0) {
                strm->avail_out = state->size;
                strm->next_out = state->out;
            }
            state->x.next = strm->next_out;
        }

        /* compress */
        have = strm->avail_out;
        ret = deflate(strm, flush);
        if (ret == Z_STREAM_ERROR) {
            gz_error(state, Z_STREAM_ERROR,
                      "internal error: deflate stream corrupt");
            return -1;
        }
        have -= strm->avail_out;
    } while (have);

    /* if that completed a deflate stream, allow another to start */
    if (flush == Z_FINISH)
        deflateReset(strm);

    /* all done, no errors */
    return 0;
}

static int gz_zero ( gz_statep  state, z_off64_t  len  )

static

{
    int first;
    unsigned n;
    z_streamp strm = &(state->strm);

    /* consume whatever's left in the input buffer */
    if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
        return -1;

    /* compress len zeros (len guaranteed > 0) */
    first = 1;
    while (len) {
        n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
            (unsigned)len : state->size;
        if (first) {
            memset(state->in, 0, n);
            first = 0;
        }
        strm->avail_in = n;
        strm->next_in = state->in;
        state->x.pos += n;
        if (gz_comp(state, Z_NO_FLUSH) == -1)
            return -1;
        len -= n;
    }
    return 0;
}

int ZEXPORT gzwrite	(	gzFile	file,
		voidpc	buf,
		unsigned	len
	)

{
    unsigned put = len;
    gz_statep state;
    z_streamp strm;

    /* get internal structure */
    if (file == NULL)
        return 0;
    state = (gz_statep)file;
    strm = &(state->strm);

    /* check that we're writing and that there's no error */
    if (state->mode != GZ_WRITE || state->err != Z_OK)
        return 0;

    /* since an int is returned, make sure len fits in one, otherwise return
       with an error (this avoids the flaw in the interface) */
    if ((int)len < 0) {
        gz_error(state, Z_DATA_ERROR, "requested length does not fit in int");
        return 0;
    }

    /* if len is zero, avoid unnecessary operations */
    if (len == 0)
        return 0;

    /* allocate memory if this is the first time through */
    if (state->size == 0 && gz_init(state) == -1)
        return 0;

    /* check for seek request */
    if (state->seek) {
        state->seek = 0;
        if (gz_zero(state, state->skip) == -1)
            return 0;
    }

    /* for small len, copy to input buffer, otherwise compress directly */
    if (len < state->size) {
        /* copy to input buffer, compress when full */
        do {
            unsigned have, copy;

            if (strm->avail_in == 0)
                strm->next_in = state->in;
            have = (unsigned)((strm->next_in + strm->avail_in) - state->in);
            copy = state->size - have;
            if (copy > len)
                copy = len;
            memcpy(state->in + have, buf, copy);
            strm->avail_in += copy;
            state->x.pos += copy;
            buf = (const char *)buf + copy;
            len -= copy;
            if (len && gz_comp(state, Z_NO_FLUSH) == -1)
                return 0;
        } while (len);
    }
    else {
        /* consume whatever's left in the input buffer */
        if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
            return 0;

        /* directly compress user buffer to file */
        strm->avail_in = len;
        strm->next_in = (z_const Bytef *)buf;
        state->x.pos += len;
        if (gz_comp(state, Z_NO_FLUSH) == -1)
            return 0;
    }

    /* input was all buffered or compressed (put will fit in int) */
    return (int)put;
}

int ZEXPORT gzputc	(	gzFile	file,
		int	c
	)

{
    unsigned have;
    unsigned char buf[1];
    gz_statep state;
    z_streamp strm;

    /* get internal structure */
    if (file == NULL)
        return -1;
    state = (gz_statep)file;
    strm = &(state->strm);

    /* check that we're writing and that there's no error */
    if (state->mode != GZ_WRITE || state->err != Z_OK)
        return -1;

    /* check for seek request */
    if (state->seek) {
        state->seek = 0;
        if (gz_zero(state, state->skip) == -1)
            return -1;
    }

    /* try writing to input buffer for speed (state->size == 0 if buffer not
       initialized) */
    if (state->size) {
        if (strm->avail_in == 0)
            strm->next_in = state->in;
        have = (unsigned)((strm->next_in + strm->avail_in) - state->in);
        if (have < state->size) {
            state->in[have] = c;
            strm->avail_in++;
            state->x.pos++;
            return c & 0xff;
        }
    }

    /* no room in buffer or not initialized, use gz_write() */
    buf[0] = c;
    if (gzwrite(file, buf, 1) != 1)
        return -1;
    return c & 0xff;
}

int ZEXPORT gzputs	(	gzFile	file,
		const char *	str
	)

{
    int ret;
    unsigned len;

    /* write string */
    len = (unsigned)strlen(str);
    ret = gzwrite(file, str, len);
    return ret == 0 && len != 0 ? -1 : ret;
}

int ZEXPORTVA gzprintf	(	gzFile	file,
		const char *	format,
		int	a1,
		int	a2,
		int	a3,
		int	a4,
		int	a5,
		int	a6,
		int	a7,
		int	a8,
		int	a9,
		int	a10,
		int	a11,
		int	a12,
		int	a13,
		int	a14,
		int	a15,
		int	a16,
		int	a17,
		int	a18,
		int	a19,
		int	a20
	)

{
    int size, len;
    gz_statep state;
    z_streamp strm;

    /* get internal structure */
    if (file == NULL)
        return -1;
    state = (gz_statep)file;
    strm = &(state->strm);

    /* check that can really pass pointer in ints */
    if (sizeof(int) != sizeof(void *))
        return 0;

    /* check that we're writing and that there's no error */
    if (state->mode != GZ_WRITE || state->err != Z_OK)
        return 0;

    /* make sure we have some buffer space */
    if (state->size == 0 && gz_init(state) == -1)
        return 0;

    /* check for seek request */
    if (state->seek) {
        state->seek = 0;
        if (gz_zero(state, state->skip) == -1)
            return 0;
    }

    /* consume whatever's left in the input buffer */
    if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
        return 0;

    /* do the printf() into the input buffer, put length in len */
    size = (int)(state->size);
    state->in[size - 1] = 0;
#ifdef NO_snprintf
#  ifdef HAS_sprintf_void
    sprintf((char *)(state->in), format, a1, a2, a3, a4, a5, a6, a7, a8,
            a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
    for (len = 0; len < size; len++)
        if (state->in[len] == 0) break;
#  else
    len = sprintf((char *)(state->in), format, a1, a2, a3, a4, a5, a6, a7, a8,
                  a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
#  endif
#else
#  ifdef HAS_snprintf_void
    snprintf((char *)(state->in), size, format, a1, a2, a3, a4, a5, a6, a7, a8,
             a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
    len = strlen((char *)(state->in));
#  else
    len = snprintf((char *)(state->in), size, format, a1, a2, a3, a4, a5, a6,
                   a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18,
                   a19, a20);
#  endif
#endif

    /* check that printf() results fit in buffer */
    if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
        return 0;

    /* update buffer and position, defer compression until needed */
    strm->avail_in = (unsigned)len;
    strm->next_in = state->in;
    state->x.pos += len;
    return len;
}

int ZEXPORT gzflush	(	gzFile	file,
		int	flush
	)

{
    gz_statep state;

    /* get internal structure */
    if (file == NULL)
        return -1;
    state = (gz_statep)file;

    /* check that we're writing and that there's no error */
    if (state->mode != GZ_WRITE || state->err != Z_OK)
        return Z_STREAM_ERROR;

    /* check flush parameter */
    if (flush < 0 || flush > Z_FINISH)
        return Z_STREAM_ERROR;

    /* check for seek request */
    if (state->seek) {
        state->seek = 0;
        if (gz_zero(state, state->skip) == -1)
            return -1;
    }

    /* compress remaining data with requested flush */
    gz_comp(state, flush);
    return state->err;
}

int ZEXPORT gzsetparams	(	gzFile	file,
		int	level,
		int	strategy
	)

{
    gz_statep state;
    z_streamp strm;

    /* get internal structure */
    if (file == NULL)
        return Z_STREAM_ERROR;
    state = (gz_statep)file;
    strm = &(state->strm);

    /* check that we're writing and that there's no error */
    if (state->mode != GZ_WRITE || state->err != Z_OK)
        return Z_STREAM_ERROR;

    /* if no change is requested, then do nothing */
    if (level == state->level && strategy == state->strategy)
        return Z_OK;

    /* check for seek request */
    if (state->seek) {
        state->seek = 0;
        if (gz_zero(state, state->skip) == -1)
            return -1;
    }

    /* change compression parameters for subsequent input */
    if (state->size) {
        /* flush previous input with previous parameters before changing */
        if (strm->avail_in && gz_comp(state, Z_PARTIAL_FLUSH) == -1)
            return state->err;
        deflateParams(strm, level, strategy);
    }
    state->level = level;
    state->strategy = strategy;
    return Z_OK;
}

int ZEXPORT gzclose_w

(

gzFile

file

)

{
    int ret = Z_OK;
    gz_statep state;

    /* get internal structure */
    if (file == NULL)
        return Z_STREAM_ERROR;
    state = (gz_statep)file;

    /* check that we're writing */
    if (state->mode != GZ_WRITE)
        return Z_STREAM_ERROR;

    /* check for seek request */
    if (state->seek) {
        state->seek = 0;
        if (gz_zero(state, state->skip) == -1)
            ret = state->err;
    }

    /* flush, free memory, and close file */
    if (gz_comp(state, Z_FINISH) == -1)
        ret = state->err;
    if (state->size) {
        if (!state->direct) {
            (void)deflateEnd(&(state->strm));
            free(state->out);
        }
        free(state->in);
    }
    gz_error(state, Z_OK, NULL);
    free(state->path);
    if (close(state->fd) == -1)
        ret = Z_ERRNO;
    free(state);
    return ret;
}