FreeBSD/Linux Kernel Cross Reference
sys/contrib/zlib/gzwrite.c

     /* gzwrite.c -- zlib functions for writing gzip files
      * Copyright (C) 2004-2019 Mark Adler
      * For conditions of distribution and use, see copyright notice in zlib.h
      */
     
     /* $FreeBSD$ */
     
     #include "gzguts.h"
     #include <unistd.h>
    
    /* Local functions */
    local int gz_init OF((gz_statep));
    local int gz_comp OF((gz_statep, int));
    local int gz_zero OF((gz_statep, z_off64_t));
    local z_size_t gz_write OF((gz_statep, voidpc, z_size_t));
    
    /* Initialize state for writing a gzip file.  Mark initialization by setting
       state->size to non-zero.  Return -1 on a memory allocation failure, or 0 on
       success. */
    local int gz_init(state)
        gz_statep state;
    {
        int ret;
        z_streamp strm = &(state->strm);
    
        /* allocate input buffer (double size for gzprintf) */
        state->in = (unsigned char *)malloc(state->want << 1);
        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;
            }
            strm->next_in = NULL;
        }
    
        /* 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;
    }
    
    /* Compress whatever is at avail_in and next_in and write to the output file.
       Return -1 if there is an error writing to the output file or if gz_init()
       fails to allocate memory, otherwise 0.  flush is assumed to be a valid
       deflate() flush value.  If flush is Z_FINISH, then the deflate() state is
       reset to start a new gzip stream.  If gz->direct is true, then simply write
       to the output file without compressing, and ignore flush. */
    local int gz_comp(state, flush)
        gz_statep state;
        int flush;
    {
        int ret, writ;
        unsigned have, put, max = ((unsigned)-1 >> 2) + 1;
        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) {
            while (strm->avail_in) {
                put = strm->avail_in > max ? max : strm->avail_in;
                writ = write(state->fd, strm->next_in, put);
                if (writ < 0) {
                    gz_error(state, Z_ERRNO, zstrerror());
                    return -1;
                }
                strm->avail_in -= (unsigned)writ;
                strm->next_in += writ;
            }
           return 0;
       }
   
       /* check for a pending reset */
       if (state->reset) {
           /* don't start a new gzip member unless there is data to write */
           if (strm->avail_in == 0)
               return 0;
           deflateReset(strm);
           state->reset = 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))) {
               while (strm->next_out > state->x.next) {
                   put = strm->next_out - state->x.next > (int)max ? max :
                         (unsigned)(strm->next_out - state->x.next);
                   writ = write(state->fd, state->x.next, put);
                   if (writ < 0) {
                       gz_error(state, Z_ERRNO, zstrerror());
                       return -1;
                   }
                   state->x.next += writ;
               }
               if (strm->avail_out == 0) {
                   strm->avail_out = state->size;
                   strm->next_out = state->out;
                   state->x.next = state->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)
           state->reset = 1;
   
       /* all done, no errors */
       return 0;
   }
   
   /* Compress len zeros to output.  Return -1 on a write error or memory
      allocation failure by gz_comp(), or 0 on success. */
   local int gz_zero(state, len)
       gz_statep state;
       z_off64_t len;
   {
       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;
   }
   
   /* Write len bytes from buf to file.  Return the number of bytes written.  If
      the returned value is less than len, then there was an error. */
   local z_size_t gz_write(state, buf, len)
       gz_statep state;
       voidpc buf;
       z_size_t len;
   {
       z_size_t put = len;
   
       /* 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 (state->strm.avail_in == 0)
                   state->strm.next_in = state->in;
               have = (unsigned)((state->strm.next_in + state->strm.avail_in) -
                                 state->in);
               copy = state->size - have;
               if (copy > len)
                   copy = (unsigned)len;
               memcpy(state->in + have, buf, copy);
               state->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 (state->strm.avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
               return 0;
   
           /* directly compress user buffer to file */
           state->strm.next_in = (z_const Bytef *)buf;
           do {
               unsigned n = (unsigned)-1;
               if (n > len)
                   n = (unsigned)len;
               state->strm.avail_in = n;
               state->x.pos += n;
               if (gz_comp(state, Z_NO_FLUSH) == -1)
                   return 0;
               len -= n;
           } while (len);
       }
   
       /* input was all buffered or compressed */
       return put;
   }
   
   /* -- see zlib.h -- */
   int ZEXPORT gzwrite(file, buf, len)
       gzFile file;
       voidpc buf;
       unsigned len;
   {
       gz_statep state;
   
       /* get internal structure */
       if (file == NULL)
           return 0;
       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 0;
   
       /* since an int is returned, make sure len fits in one, otherwise return
          with an error (this avoids a flaw in the interface) */
       if ((int)len < 0) {
           gz_error(state, Z_DATA_ERROR, "requested length does not fit in int");
           return 0;
       }
   
       /* write len bytes from buf (the return value will fit in an int) */
       return (int)gz_write(state, buf, len);
   }
   
   /* -- see zlib.h -- */
   z_size_t ZEXPORT gzfwrite(buf, size, nitems, file)
       voidpc buf;
       z_size_t size;
       z_size_t nitems;
       gzFile file;
   {
       z_size_t len;
       gz_statep state;
   
       /* get internal structure */
       if (file == NULL)
           return 0;
       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 0;
   
       /* compute bytes to read -- error on overflow */
       len = nitems * size;
       if (size && len / size != nitems) {
           gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t");
           return 0;
       }
   
       /* write len bytes to buf, return the number of full items written */
       return len ? gz_write(state, buf, len) / size : 0;
   }
   
   /* -- see zlib.h -- */
   int ZEXPORT gzputc(file, c)
       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] = (unsigned char)c;
               strm->avail_in++;
               state->x.pos++;
               return c & 0xff;
           }
       }
   
       /* no room in buffer or not initialized, use gz_write() */
       buf[0] = (unsigned char)c;
       if (gz_write(state, buf, 1) != 1)
           return -1;
       return c & 0xff;
   }
   
   /* -- see zlib.h -- */
   int ZEXPORT gzputs(file, s)
       gzFile file;
       const char *s;
   {
       z_size_t len, put;
       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 -1;
   
       /* write string */
       len = strlen(s);
       if ((int)len < 0 || (unsigned)len != len) {
           gz_error(state, Z_STREAM_ERROR, "string length does not fit in int");
           return -1;
       }
       put = gz_write(state, s, len);
       return put < len ? -1 : (int)len;
   }
   
   #if defined(STDC) || defined(Z_HAVE_STDARG_H)
   #include <stdarg.h>
   
   /* -- see zlib.h -- */
   int ZEXPORTVA gzvprintf(gzFile file, const char *format, va_list va)
   {
       int len;
       unsigned left;
       char *next;
       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;
   
       /* make sure we have some buffer space */
       if (state->size == 0 && gz_init(state) == -1)
           return state->err;
   
       /* check for seek request */
       if (state->seek) {
           state->seek = 0;
           if (gz_zero(state, state->skip) == -1)
               return state->err;
       }
   
       /* do the printf() into the input buffer, put length in len -- the input
          buffer is double-sized just for this function, so there is guaranteed to
          be state->size bytes available after the current contents */
       if (strm->avail_in == 0)
           strm->next_in = state->in;
       next = (char *)(state->in + (strm->next_in - state->in) + strm->avail_in);
       next[state->size - 1] = 0;
   #ifdef NO_vsnprintf
   #  ifdef HAS_vsprintf_void
       (void)vsprintf(next, format, va);
       for (len = 0; len < state->size; len++)
           if (next[len] == 0) break;
   #  else
       len = vsprintf(next, format, va);
   #  endif
   #else
   #  ifdef HAS_vsnprintf_void
       (void)vsnprintf(next, state->size, format, va);
       len = strlen(next);
   #  else
       len = vsnprintf(next, state->size, format, va);
   #  endif
   #endif
   
       /* check that printf() results fit in buffer */
       if (len == 0 || (unsigned)len >= state->size || next[state->size - 1] != 0)
           return 0;
   
       /* update buffer and position, compress first half if past that */
       strm->avail_in += (unsigned)len;
       state->x.pos += len;
       if (strm->avail_in >= state->size) {
           left = strm->avail_in - state->size;
           strm->avail_in = state->size;
           if (gz_comp(state, Z_NO_FLUSH) == -1)
               return state->err;
           memmove(state->in, state->in + state->size, left);
           strm->next_in = state->in;
           strm->avail_in = left;
       }
       return len;
   }
   
   int ZEXPORTVA gzprintf(gzFile file, const char *format, ...)
   {
       va_list va;
       int ret;
   
       va_start(va, format);
       ret = gzvprintf(file, format, va);
       va_end(va);
       return ret;
   }
   
   #else /* !STDC && !Z_HAVE_STDARG_H */
   
   /* -- see zlib.h -- */
   int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
                          a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
       gzFile file;
       const char *format;
       int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
           a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
   {
       unsigned len, left;
       char *next;
       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 can really pass pointer in ints */
       if (sizeof(int) != sizeof(void *))
           return Z_STREAM_ERROR;
   
       /* check that we're writing and that there's no error */
       if (state->mode != GZ_WRITE || state->err != Z_OK)
           return Z_STREAM_ERROR;
   
       /* make sure we have some buffer space */
       if (state->size == 0 && gz_init(state) == -1)
           return state->error;
   
       /* check for seek request */
       if (state->seek) {
           state->seek = 0;
           if (gz_zero(state, state->skip) == -1)
               return state->error;
       }
   
       /* do the printf() into the input buffer, put length in len -- the input
          buffer is double-sized just for this function, so there is guaranteed to
          be state->size bytes available after the current contents */
       if (strm->avail_in == 0)
           strm->next_in = state->in;
       next = (char *)(strm->next_in + strm->avail_in);
       next[state->size - 1] = 0;
   #ifdef NO_snprintf
   #  ifdef HAS_sprintf_void
       sprintf(next, 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 (next[len] == 0)
               break;
   #  else
       len = sprintf(next, 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(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8, a9,
                a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
       len = strlen(next);
   #  else
       len = snprintf(next, state->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 >= state->size || next[state->size - 1] != 0)
           return 0;
   
       /* update buffer and position, compress first half if past that */
       strm->avail_in += len;
       state->x.pos += len;
       if (strm->avail_in >= state->size) {
           left = strm->avail_in - state->size;
           strm->avail_in = state->size;
           if (gz_comp(state, Z_NO_FLUSH) == -1)
               return state->err;
           memmove(state->in, state->in + state->size, left);
           strm->next_in = state->in;
           strm->avail_in = left;
       }
       return (int)len;
   }
   
   #endif
   
   /* -- see zlib.h -- */
   int ZEXPORT gzflush(file, flush)
       gzFile file;
       int flush;
   {
       gz_statep state;
   
       /* get internal structure */
       if (file == NULL)
           return Z_STREAM_ERROR;
       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 state->err;
       }
   
       /* compress remaining data with requested flush */
       (void)gz_comp(state, flush);
       return state->err;
   }
   
   /* -- see zlib.h -- */
   int ZEXPORT gzsetparams(file, level, strategy)
       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 state->err;
       }
   
       /* 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_BLOCK) == -1)
               return state->err;
           deflateParams(strm, level, strategy);
       }
       state->level = level;
       state->strategy = strategy;
       return Z_OK;
   }
   
   /* -- see zlib.h -- */
   int ZEXPORT gzclose_w(file)
       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;
   }

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