+static void
+png_write_complete_chunk(png_structp png_ptr, png_uint_32 chunk_name,
+ png_const_bytep data, png_size_t length)
+{
+ if (png_ptr == NULL)
+ return;
+
+ /* On 64 bit architectures 'length' may not fit in a png_uint_32. */
+ if (length > PNG_UINT_32_MAX)
+ png_error(png_ptr, "length exceeds PNG maxima");
+
+ png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length);
+ png_write_chunk_data(png_ptr, data, length);
+ png_write_chunk_end(png_ptr);
+}
+
+/* This is the API that calls the internal function above. */
+void PNGAPI
+png_write_chunk(png_structp png_ptr, png_const_bytep chunk_string,
+ png_const_bytep data, png_size_t length)
+{
+ png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data,
+ length);
+}
+
+/* Initialize the compressor for the appropriate type of compression. */
+static void
+png_zlib_claim(png_structp png_ptr, png_uint_32 state)
+{
+ if (!(png_ptr->zlib_state & PNG_ZLIB_IN_USE))
+ {
+ /* If already initialized for 'state' do not re-init. */
+ if (png_ptr->zlib_state != state)
+ {
+ int ret = Z_OK;
+ png_const_charp who = "-";
+
+ /* If actually initialized for another state do a deflateEnd. */
+ if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED)
+ {
+ ret = deflateEnd(&png_ptr->zstream);
+ who = "end";
+ png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED;
+ }
+
+ /* zlib itself detects an incomplete state on deflateEnd */
+ if (ret == Z_OK) switch (state)
+ {
+# ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+ case PNG_ZLIB_FOR_TEXT:
+ ret = deflateInit2(&png_ptr->zstream,
+ png_ptr->zlib_text_level, png_ptr->zlib_text_method,
+ png_ptr->zlib_text_window_bits,
+ png_ptr->zlib_text_mem_level, png_ptr->zlib_text_strategy);
+ who = "text";
+ break;
+# endif
+
+ case PNG_ZLIB_FOR_IDAT:
+ ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
+ png_ptr->zlib_method, png_ptr->zlib_window_bits,
+ png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
+ who = "IDAT";
+ break;
+
+ default:
+ png_error(png_ptr, "invalid zlib state");
+ }
+
+ if (ret == Z_OK)
+ png_ptr->zlib_state = state;
+
+ else /* an error in deflateEnd or deflateInit2 */
+ {
+ size_t pos = 0;
+ char msg[64];
+
+ pos = png_safecat(msg, sizeof msg, pos,
+ "zlib failed to initialize compressor (");
+ pos = png_safecat(msg, sizeof msg, pos, who);
+
+ switch (ret)
+ {
+ case Z_VERSION_ERROR:
+ pos = png_safecat(msg, sizeof msg, pos, ") version error");
+ break;
+
+ case Z_STREAM_ERROR:
+ pos = png_safecat(msg, sizeof msg, pos, ") stream error");
+ break;
+
+ case Z_MEM_ERROR:
+ pos = png_safecat(msg, sizeof msg, pos, ") memory error");
+ break;
+
+ default:
+ pos = png_safecat(msg, sizeof msg, pos, ") unknown error");
+ break;
+ }
+
+ png_error(png_ptr, msg);
+ }
+ }
+
+ /* Here on success, claim the zstream: */
+ png_ptr->zlib_state |= PNG_ZLIB_IN_USE;
+ }
+
+ else
+ png_error(png_ptr, "zstream already in use (internal error)");
+}
+
+/* The opposite: release the stream. It is also reset, this API will warn on
+ * error but will not fail.
+ */
+static void
+png_zlib_release(png_structp png_ptr)
+{
+ if (png_ptr->zlib_state & PNG_ZLIB_IN_USE)
+ {
+ int ret = deflateReset(&png_ptr->zstream);
+
+ png_ptr->zlib_state &= ~PNG_ZLIB_IN_USE;
+
+ if (ret != Z_OK)
+ {
+ png_const_charp err;
+ PNG_WARNING_PARAMETERS(p)
+
+ switch (ret)
+ {
+ case Z_VERSION_ERROR:
+ err = "version";
+ break;
+
+ case Z_STREAM_ERROR:
+ err = "stream";
+ break;
+
+ case Z_MEM_ERROR:
+ err = "memory";
+ break;
+
+ default:
+ err = "unknown";
+ break;
+ }
+
+ png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, ret);
+ png_warning_parameter(p, 2, err);
+
+ if (png_ptr->zstream.msg)
+ err = png_ptr->zstream.msg;
+ else
+ err = "[no zlib message]";
+
+ png_warning_parameter(p, 3, err);
+
+ png_formatted_warning(png_ptr, p,
+ "zlib failed to reset compressor: @1(@2): @3");
+ }
+ }
+
+ else
+ png_warning(png_ptr, "zstream not in use (internal error)");
+}
+
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+/* This pair of functions encapsulates the operation of (a) compressing a
+ * text string, and (b) issuing it later as a series of chunk data writes.
+ * The compression_state structure is shared context for these functions
+ * set up by the caller in order to make the whole mess thread-safe.
+ */
+
+typedef struct
+{
+ png_const_bytep input; /* The uncompressed input data */
+ png_size_t input_len; /* Its length */
+ int num_output_ptr; /* Number of output pointers used */
+ int max_output_ptr; /* Size of output_ptr */
+ png_bytep *output_ptr; /* Array of pointers to output */
+} compression_state;
+
+/* Compress given text into storage in the png_ptr structure */
+static int /* PRIVATE */
+png_text_compress(png_structp png_ptr,
+ png_const_charp text, png_size_t text_len, int compression,
+ compression_state *comp)
+{
+ int ret;
+
+ comp->num_output_ptr = 0;
+ comp->max_output_ptr = 0;
+ comp->output_ptr = NULL;
+ comp->input = NULL;
+ comp->input_len = text_len;
+
+ /* We may just want to pass the text right through */
+ if (compression == PNG_TEXT_COMPRESSION_NONE)
+ {
+ comp->input = (png_const_bytep)text;
+ return((int)text_len);
+ }
+
+ if (compression >= PNG_TEXT_COMPRESSION_LAST)
+ {
+ PNG_WARNING_PARAMETERS(p)
+
+ png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d,
+ compression);
+ png_formatted_warning(png_ptr, p, "Unknown compression type @1");
+ }
+
+ /* We can't write the chunk until we find out how much data we have,
+ * which means we need to run the compressor first and save the
+ * output. This shouldn't be a problem, as the vast majority of
+ * comments should be reasonable, but we will set up an array of
+ * malloc'd pointers to be sure.
+ *
+ * If we knew the application was well behaved, we could simplify this
+ * greatly by assuming we can always malloc an output buffer large
+ * enough to hold the compressed text ((1001 * text_len / 1000) + 12)
+ * and malloc this directly. The only time this would be a bad idea is
+ * if we can't malloc more than 64K and we have 64K of random input
+ * data, or if the input string is incredibly large (although this
+ * wouldn't cause a failure, just a slowdown due to swapping).
+ */
+ png_zlib_claim(png_ptr, PNG_ZLIB_FOR_TEXT);
+
+ /* Set up the compression buffers */
+ /* TODO: the following cast hides a potential overflow problem. */
+ png_ptr->zstream.avail_in = (uInt)text_len;
+
+ /* NOTE: assume zlib doesn't overwrite the input */
+ png_ptr->zstream.next_in = (Bytef *)text;
+ png_ptr->zstream.avail_out = png_ptr->zbuf_size;
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+
+ /* This is the same compression loop as in png_write_row() */
+ do
+ {
+ /* Compress the data */
+ ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
+
+ if (ret != Z_OK)
+ {
+ /* Error */
+ if (png_ptr->zstream.msg != NULL)
+ png_error(png_ptr, png_ptr->zstream.msg);
+
+ else
+ png_error(png_ptr, "zlib error");
+ }
+
+ /* Check to see if we need more room */
+ if (!(png_ptr->zstream.avail_out))
+ {
+ /* Make sure the output array has room */
+ if (comp->num_output_ptr >= comp->max_output_ptr)
+ {
+ int old_max;
+
+ old_max = comp->max_output_ptr;
+ comp->max_output_ptr = comp->num_output_ptr + 4;
+ if (comp->output_ptr != NULL)
+ {
+ png_bytepp old_ptr;
+
+ old_ptr = comp->output_ptr;
+
+ comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
+ (png_alloc_size_t)
+ (comp->max_output_ptr * png_sizeof(png_charpp)));
+
+ png_memcpy(comp->output_ptr, old_ptr, old_max
+ * png_sizeof(png_charp));
+
+ png_free(png_ptr, old_ptr);
+ }
+ else
+ comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
+ (png_alloc_size_t)
+ (comp->max_output_ptr * png_sizeof(png_charp)));
+ }
+
+ /* Save the data */
+ comp->output_ptr[comp->num_output_ptr] =
+ (png_bytep)png_malloc(png_ptr,
+ (png_alloc_size_t)png_ptr->zbuf_size);
+
+ png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
+ png_ptr->zbuf_size);
+
+ comp->num_output_ptr++;
+
+ /* and reset the buffer */
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ }
+ /* Continue until we don't have any more to compress */
+ } while (png_ptr->zstream.avail_in);
+
+ /* Finish the compression */
+ do
+ {
+ /* Tell zlib we are finished */
+ ret = deflate(&png_ptr->zstream, Z_FINISH);
+
+ if (ret == Z_OK)
+ {
+ /* Check to see if we need more room */
+ if (!(png_ptr->zstream.avail_out))
+ {
+ /* Check to make sure our output array has room */
+ if (comp->num_output_ptr >= comp->max_output_ptr)
+ {
+ int old_max;
+
+ old_max = comp->max_output_ptr;
+ comp->max_output_ptr = comp->num_output_ptr + 4;
+ if (comp->output_ptr != NULL)
+ {
+ png_bytepp old_ptr;
+
+ old_ptr = comp->output_ptr;
+
+ /* This could be optimized to realloc() */
+ comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
+ (png_alloc_size_t)(comp->max_output_ptr *
+ png_sizeof(png_charp)));
+
+ png_memcpy(comp->output_ptr, old_ptr,
+ old_max * png_sizeof(png_charp));
+
+ png_free(png_ptr, old_ptr);
+ }
+
+ else
+ comp->output_ptr = (png_bytepp)png_malloc(png_ptr,
+ (png_alloc_size_t)(comp->max_output_ptr *
+ png_sizeof(png_charp)));
+ }
+
+ /* Save the data */
+ comp->output_ptr[comp->num_output_ptr] =
+ (png_bytep)png_malloc(png_ptr,
+ (png_alloc_size_t)png_ptr->zbuf_size);
+
+ png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
+ png_ptr->zbuf_size);
+
+ comp->num_output_ptr++;
+
+ /* and reset the buffer pointers */
+ png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
+ png_ptr->zstream.next_out = png_ptr->zbuf;
+ }
+ }
+ else if (ret != Z_STREAM_END)
+ {
+ /* We got an error */
+ if (png_ptr->zstream.msg != NULL)
+ png_error(png_ptr, png_ptr->zstream.msg);
+
+ else
+ png_error(png_ptr, "zlib error");
+ }
+ } while (ret != Z_STREAM_END);
+
+ /* Text length is number of buffers plus last buffer */
+ text_len = png_ptr->zbuf_size * comp->num_output_ptr;
+
+ if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
+ text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
+
+ return((int)text_len);
+}
+
+/* Ship the compressed text out via chunk writes */
+static void /* PRIVATE */
+png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
projects / wxWidgets.git / blobdiff