int ZEXPORT gzwrite()

in activemq-cpp/src/main/decaf/internal/util/zip/gzwrite.c [143:218]
55 lines of code
19 McCabe index (conditional complexity)

int ZEXPORT gzwrite(file, buf, len)
    gzFile file;
    voidpc buf;
    unsigned len;
{
    unsigned put = len;
    unsigned n;
    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_BUF_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 {
            if (strm->avail_in == 0)
                strm->next_in = state->in;
            n = state->size - strm->avail_in;
            if (n > len)
                n = len;
            memcpy(strm->next_in + strm->avail_in, buf, n);
            strm->avail_in += n;
            state->pos += n;
            buf = (char *)buf + n;
            len -= n;
            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 = (voidp)buf;
        state->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;
}