Add cairo-deflate-stream.c

Add a new stream type that compresses the stream using the zlib deflate method.
This is intended for use by the PDF surface.

src/Makefile.am

@@ -177,6 +177,7 @@ libcairo_la_SOURCES =				\
 	cairo-clip-private.h			\
 	cairo-color.c				\
 	cairo-debug.c				\
+	cairo-deflate-stream.c			\
 	cairo-fixed.c				\
 	cairo-font.c				\
 	cairo-font-options.c			\

src/cairo-deflate-stream.c

@@ -0,0 +1,142 @@
+/* cairo_deflate_stream.c: Output stream abstraction
+ *
+ * Copyright © 2006 Adrian Johnson
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it either under the terms of the GNU Lesser General Public
+ * License version 2.1 as published by the Free Software Foundation
+ * (the "LGPL") or, at your option, under the terms of the Mozilla
+ * Public License Version 1.1 (the "MPL"). If you do not alter this
+ * notice, a recipient may use your version of this file under either
+ * the MPL or the LGPL.
+ *
+ * You should have received a copy of the LGPL along with this library
+ * in the file COPYING-LGPL-2.1; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * You should have received a copy of the MPL along with this library
+ * in the file COPYING-MPL-1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
+ * OF ANY KIND, either express or implied. See the LGPL or the MPL for
+ * the specific language governing rights and limitations.
+ *
+ * The Original Code is cairo_output_stream.c as distributed with the
+ *   cairo graphics library.
+ *
+ * The Initial Developer of the Original Code is Adrian Johnson.
+ *
+ * Author(s):
+ *	Adrian Johnson <ajohnson@redneon.com>
+ */
+
+#include "cairoint.h"
+#include "cairo-output-stream-private.h"
+#include <zlib.h>
+
+#define BUFFER_SIZE 16384
+
+typedef struct _cairo_deflate_stream {
+    cairo_output_stream_t  base;
+    cairo_output_stream_t *output;
+    z_stream               zlib_stream;
+    unsigned char          input_buf[BUFFER_SIZE];
+    unsigned char          output_buf[BUFFER_SIZE];
+} cairo_deflate_stream_t;
+
+static void
+cairo_deflate_stream_deflate (cairo_deflate_stream_t *stream, cairo_bool_t flush)
+{
+    int ret;
+    cairo_bool_t finished;
+
+    do {
+        ret = deflate (&stream->zlib_stream, flush ? Z_FINISH : Z_NO_FLUSH);
+        if (flush || stream->zlib_stream.avail_out == 0)
+        {
+            _cairo_output_stream_write (stream->output,
+                                        stream->output_buf,
+                                        BUFFER_SIZE - stream->zlib_stream.avail_out);
+            stream->zlib_stream.next_out = stream->output_buf;
+            stream->zlib_stream.avail_out = BUFFER_SIZE;
+        }
+
+        finished = TRUE;
+        if (stream->zlib_stream.avail_in != 0)
+            finished = FALSE;
+        if (flush && ret != Z_STREAM_END)
+            finished = FALSE;
+
+    } while (!finished);
+
+    stream->zlib_stream.next_in = stream->input_buf;
+}
+
+static cairo_status_t
+_cairo_deflate_stream_write (cairo_output_stream_t *base,
+                             const unsigned char   *data,
+                             unsigned int	    length)
+{
+    cairo_deflate_stream_t *stream = (cairo_deflate_stream_t *) base;
+    unsigned int count;
+    const unsigned char *p = data;
+
+    while (length) {
+        count = length;
+        if (count > BUFFER_SIZE - stream->zlib_stream.avail_in)
+            count = BUFFER_SIZE - stream->zlib_stream.avail_in;
+        memcpy (stream->input_buf + stream->zlib_stream.avail_in, p, count);
+        p += count;
+        stream->zlib_stream.avail_in += count;
+        length -= count;
+
+        if (stream->zlib_stream.avail_in == BUFFER_SIZE)
+            cairo_deflate_stream_deflate (stream, FALSE);
+    }
+
+    return _cairo_output_stream_get_status (stream->output);
+}
+
+static cairo_status_t
+_cairo_deflate_stream_close (cairo_output_stream_t *base)
+{
+    cairo_deflate_stream_t *stream = (cairo_deflate_stream_t *) base;
+
+    cairo_deflate_stream_deflate (stream, TRUE);
+    deflateEnd (&stream->zlib_stream);
+
+    return _cairo_output_stream_get_status (stream->output);
+}
+
+cairo_output_stream_t *
+_cairo_deflate_stream_create (cairo_output_stream_t *output)
+{
+    cairo_deflate_stream_t *stream;
+
+    stream = malloc (sizeof (cairo_deflate_stream_t));
+    if (stream == NULL)
+	return (cairo_output_stream_t *) &cairo_output_stream_nil;
+
+    _cairo_output_stream_init (&stream->base,
+			       _cairo_deflate_stream_write,
+			       _cairo_deflate_stream_close);
+    stream->output = output;
+
+    stream->zlib_stream.zalloc = Z_NULL;
+    stream->zlib_stream.zfree  = Z_NULL;
+    stream->zlib_stream.opaque  = Z_NULL;
+
+    if (deflateInit (&stream->zlib_stream, Z_DEFAULT_COMPRESSION) != Z_OK)
+	return (cairo_output_stream_t *) &cairo_output_stream_nil;
+
+    stream->zlib_stream.next_in = stream->input_buf;
+    stream->zlib_stream.avail_in = 0;
+    stream->zlib_stream.next_out = stream->output_buf;
+    stream->zlib_stream.avail_out = BUFFER_SIZE;
+
+    return &stream->base;
+}

src/cairo-output-stream-private.h

@@ -159,4 +159,8 @@ _cairo_memory_stream_length (cairo_output_stream_t *stream);
 cairo_private cairo_output_stream_t *
 _cairo_base85_stream_create (cairo_output_stream_t *output);
 
+/* cairo_deflate_stream.c */
+cairo_private cairo_output_stream_t *
+_cairo_deflate_stream_create (cairo_output_stream_t *output);
+
 #endif /* CAIRO_OUTPUT_STREAM_PRIVATE_H */