support/zlib-helper.c

   1 /*
   2  * Used by System.IO.Compression.DeflateStream
   3  *
   4  * Author:
   5  *   Gonzalo Paniagua Javier (gonzalo@novell.com)
   6  *
   7  * (c) Copyright 2009 Novell, Inc.
   8  */
   9 #include <config.h>
  10 #if defined (HAVE_SYS_ZLIB)
  11 #include <zlib.h>
  12 #else
  13 #include "zlib.h"
  14 #endif
  15
  16 #include <glib.h>
  17 #include <string.h>
  18 #include <stdlib.h>
  19
  20 #ifndef MONO_API
  21 #define MONO_API
  22 #endif
  23
  24 #ifndef TRUE
  25 #define FALSE 0
  26 #define TRUE 1
  27 #endif
  28
  29 #define BUFFER_SIZE 4096
  30 #define ARGUMENT_ERROR -10
  31 #define IO_ERROR -11
  32 #define MONO_EXCEPTION -12
  33
  34 #define z_new0(type)  ((type *) calloc (sizeof (type), 1))
  35
  36 typedef gint (*read_write_func) (guchar *buffer, gint length, void *gchandle);
  37 struct _ZStream {
  38         z_stream *stream;
  39         guchar *buffer;
  40         read_write_func func;
  41         void *gchandle;
  42         guchar compress;
  43         guchar eof;
  44         guint32 total_in;
  45 };
  46 typedef struct _ZStream ZStream;
  47
  48 // FIXME? Names should start "mono"?
  49 MONO_API ZStream *CreateZStream (gint compress, guchar gzip, read_write_func func, void *gchandle);
  50 MONO_API gint CloseZStream (ZStream *zstream);
  51 MONO_API gint Flush (ZStream *stream);
  52 MONO_API gint ReadZStream (ZStream *stream, guchar *buffer, gint length);
  53 MONO_API gint WriteZStream (ZStream *stream, guchar *buffer, gint length);
  54 static gint flush_internal (ZStream *stream, gboolean is_final);
  55
  56 static void *
  57 z_alloc (void *opaque, unsigned int nitems, unsigned int item_size)
  58 {
  59         return calloc (nitems, item_size);
  60 }
  61
  62 static void
  63 z_free (void *opaque, void *ptr)
  64 {
  65         free (ptr);
  66 }
  67
  68 ZStream *
  69 CreateZStream (gint compress, guchar gzip, read_write_func func, void *gchandle)
  70 {
  71         z_stream *z;
  72         gint retval;
  73         ZStream *result;
  74
  75         if (func == NULL)
  76                 return NULL;
  77
  78         z = z_new0 (z_stream);
  79         if (compress) {
  80                 retval = deflateInit2 (z, Z_DEFAULT_COMPRESSION, Z_DEFLATED, gzip ? 31 : -15, 8, Z_DEFAULT_STRATEGY);
  81         } else {
  82                 retval = inflateInit2 (z, gzip ? 31 : -15);
  83         }
  84
  85         if (retval != Z_OK) {
  86                 free (z);
  87                 return NULL;
  88         }
  89         z->zalloc = z_alloc;
  90         z->zfree = z_free;
  91         result = z_new0 (ZStream);
  92         result->stream = z;
  93         result->func = func;
  94         result->gchandle = gchandle;
  95         result->compress = compress;
  96         result->buffer = (guchar*)malloc (BUFFER_SIZE);
  97         result->stream->next_out = result->buffer;
  98         result->stream->avail_out = BUFFER_SIZE;
  99         result->stream->total_in = 0;
 100         return result;
 101 }
 102
 103 gint
 104 CloseZStream (ZStream *zstream)
 105 {
 106         gint status;
 107         gint flush_status;
 108
 109         if (zstream == NULL)
 110                 return ARGUMENT_ERROR;
 111
 112         status = 0;
 113         if (zstream->compress) {
 114                 if (zstream->stream->total_in > 0) {
 115                         do {
 116                                 status = deflate (zstream->stream, Z_FINISH);
 117                                 flush_status = flush_internal (zstream, TRUE);
 118                                 if (flush_status == MONO_EXCEPTION) {
 119                                         status = flush_status;
 120                                         break;
 121                                 }
 122                         } while (status == Z_OK); /* We want Z_STREAM_END or error here here */
 123                         if (status == Z_STREAM_END)
 124                                 status = flush_status;
 125                 }
 126                 deflateEnd (zstream->stream);
 127         } else {
 128                 inflateEnd (zstream->stream);
 129         }
 130         free (zstream->buffer);
 131         free (zstream->stream);
 132         memset (zstream, 0, sizeof (ZStream));
 133         free (zstream);
 134         return status;
 135 }
 136
 137 static gint
 138 write_to_managed (ZStream *stream)
 139 {
 140         gint n;
 141         z_stream *zs;
 142
 143         zs = stream->stream;
 144         if (zs->avail_out != BUFFER_SIZE) {
 145                 n = stream->func (stream->buffer, BUFFER_SIZE - zs->avail_out, stream->gchandle);
 146                 zs->next_out = stream->buffer;
 147                 zs->avail_out = BUFFER_SIZE;
 148                 if (n == MONO_EXCEPTION)
 149                         return n;
 150                 if (n < 0)
 151                         return IO_ERROR;
 152         }
 153         return 0;
 154 }
 155
 156 static gint
 157 flush_internal (ZStream *stream, gboolean is_final)
 158 {
 159         gint status;
 160
 161         if (!stream->compress)
 162                 return 0;
 163
 164         if (!is_final && stream->stream->avail_in != 0) {
 165                 status = deflate (stream->stream, Z_PARTIAL_FLUSH);
 166                 if (status != Z_OK && status != Z_STREAM_END)
 167                         return status;
 168         }
 169         return write_to_managed (stream);
 170 }
 171
 172 gint
 173 Flush (ZStream *stream)
 174 {
 175         return flush_internal (stream, FALSE);
 176 }
 177
 178 gint
 179 ReadZStream (ZStream *stream, guchar *buffer, gint length)
 180 {
 181         gint n;
 182         gint status;
 183         z_stream *zs;
 184
 185         if (stream == NULL || buffer == NULL || length < 0)
 186                 return ARGUMENT_ERROR;
 187
 188         if (stream->eof)
 189                 return 0;
 190
 191         zs = stream->stream;
 192         zs->next_out = buffer;
 193         zs->avail_out = length;
 194         while (zs->avail_out > 0) {
 195                 if (zs->avail_in == 0) {
 196                         n = stream->func (stream->buffer, BUFFER_SIZE, stream->gchandle);
 197                         n = n < 0 ? 0 : n;
 198                         stream->total_in += n;
 199                         zs->next_in = stream->buffer;
 200                         zs->avail_in = n;
 201                 }
 202
 203                 if (zs->avail_in == 0 && zs->total_in == 0)
 204                         return 0;
 205
 206                 status = inflate (stream->stream, Z_SYNC_FLUSH);
 207                 if (status == Z_STREAM_END) {
 208                         stream->eof = TRUE;
 209                         break;
 210                 } else if (status == Z_BUF_ERROR && stream->total_in == zs->total_in) {
 211                         if (zs->avail_in != 0) {
 212                                 stream->eof = TRUE;
 213                         }
 214                         break;
 215                 } else if (status != Z_OK) {
 216                         return status;
 217                 }
 218         }
 219         return length - zs->avail_out;
 220 }
 221
 222 gint
 223 WriteZStream (ZStream *stream, guchar *buffer, gint length)
 224 {
 225         gint n;
 226         gint status;
 227         z_stream *zs;
 228
 229         if (stream == NULL || buffer == NULL || length < 0)
 230                 return ARGUMENT_ERROR;
 231
 232         if (stream->eof)
 233                 return IO_ERROR;
 234
 235         zs = stream->stream;
 236         zs->next_in = buffer;
 237         zs->avail_in = length;
 238         while (zs->avail_in > 0) {
 239                 if (zs->avail_out == 0) {
 240                         zs->next_out = stream->buffer;
 241                         zs->avail_out = BUFFER_SIZE;
 242                 }
 243                 status = deflate (stream->stream, Z_NO_FLUSH);
 244                 if (status != Z_OK && status != Z_STREAM_END)
 245                         return status;
 246
 247                 if (zs->avail_out == 0) {
 248                         n = write_to_managed (stream);
 249                         if (n < 0)
 250                                 return n;
 251                 }
 252         }
 253         return length;
 254 }
 255