Adding upstream version 1:2.3.19.1+dfsg1.upstream/1%2.3.19.1+dfsg1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 307 insertions, 0 deletions

diff --git a/src/lib-compression/ostream-bzlib.c b/src/lib-compression/ostream-bzlib.c
new file mode 100644
index 0000000..4d072b2
--- /dev/null
+++ b/src/lib-compression/ostream-bzlib.c
@@ -0,0 +1,307 @@
+/* Copyright (c) 2010-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+
+#ifdef HAVE_BZLIB
+
+#include "ostream-private.h"
+#include "ostream-zlib.h"
+#include <bzlib.h>
+
+#define CHUNK_SIZE (1024*64)
+
+struct bzlib_ostream {
+	struct ostream_private ostream;
+	bz_stream zs;
+
+	char outbuf[CHUNK_SIZE];
+	unsigned int outbuf_offset, outbuf_used;
+
+	bool flushed:1;
+};
+
+/* in bzlib, level is actually block size. From bzlib manual:
+
+   The block size affects both the compression ratio achieved,
+   and the amount of memory needed for compression and decompression.
+
+   BlockSize 1 through BlockSize 9 specify the block size to be 100,000 bytes
+   through 900,000 bytes respectively. The default is to use the maximum block
+   size.
+
+   Larger block sizes give rapidly diminishing marginal returns.
+   Most of the compression comes from the first two or three hundred k of
+   block size, a fact worth bearing in mind when using bzip2 on small machines.
+   It is also important to appreciate that the decompression memory
+   requirement is set at compression time by the choice of block size.
+
+   * In general, try and use the largest block size memory constraints
+     allow, since that maximises the compression achieved.
+   * Compression and decompression speed are virtually unaffected by block
+     size.
+
+   Another significant point applies to files which fit in a single block -
+   that means most files you'd encounter using a large block size. The
+   amount of real memory touched is proportional to the size of the file,
+   since the file is smaller than a block. For example, compressing a file
+   20,000 bytes long with the flag BlockSize 9 will cause the compressor to
+   allocate around 7600k of memory, but only touch 400k + 20000 * 8 = 560 kbytes
+   of it. Similarly, the decompressor will allocate 3700k but only
+   touch 100k + 20000 * 4 = 180 kbytes.
+*/
+
+int compression_get_min_level_bz2(void)
+{
+	return 1;
+}
+
+int compression_get_default_level_bz2(void)
+{
+	/* default is maximum level */
+	return 9;
+}
+
+int compression_get_max_level_bz2(void)
+{
+	return 9;
+}
+
+static void o_stream_bzlib_close(struct iostream_private *stream,
+				 bool close_parent)
+{
+	struct bzlib_ostream *zstream = (struct bzlib_ostream *)stream;
+
+	(void)BZ2_bzCompressEnd(&zstream->zs);
+	if (close_parent)
+		o_stream_close(zstream->ostream.parent);
+}
+
+static int o_stream_zlib_send_outbuf(struct bzlib_ostream *zstream)
+{
+	ssize_t ret;
+	size_t size;
+
+	if (zstream->outbuf_used == 0)
+		return 1;
+
+	size = zstream->outbuf_used - zstream->outbuf_offset;
+	i_assert(size > 0);
+	ret = o_stream_send(zstream->ostream.parent,
+			    zstream->outbuf + zstream->outbuf_offset, size);
+	if (ret < 0) {
+		o_stream_copy_error_from_parent(&zstream->ostream);
+		return -1;
+	}
+	if ((size_t)ret != size) {
+		zstream->outbuf_offset += ret;
+		return 0;
+	}
+	zstream->outbuf_offset = 0;
+	zstream->outbuf_used = 0;
+	return 1;
+}
+
+static ssize_t
+o_stream_bzlib_send_chunk(struct bzlib_ostream *zstream,
+			  const void *data, size_t size)
+{
+	bz_stream *zs = &zstream->zs;
+	int ret;
+
+	i_assert(zstream->outbuf_used == 0);
+
+	zs->next_in = (void *)data;
+	zs->avail_in = size;
+	while (zs->avail_in > 0) {
+		if (zs->avail_out == 0) {
+			/* previous block was compressed. send it and start
+			   compression for a new block. */
+			zs->next_out = zstream->outbuf;
+			zs->avail_out = sizeof(zstream->outbuf);
+
+			zstream->outbuf_used = sizeof(zstream->outbuf);
+			if ((ret = o_stream_zlib_send_outbuf(zstream)) < 0)
+				return -1;
+			if (ret == 0) {
+				/* parent stream's buffer full */
+				break;
+			}
+		}
+
+		switch ((ret = BZ2_bzCompress(zs, BZ_RUN))) {
+		case BZ_RUN_OK:
+			break;
+		case BZ_MEM_ERROR:
+			i_fatal_status(FATAL_OUTOFMEM, "bzip2.write(%s): Out of memory",
+				       o_stream_get_name(&zstream->ostream.ostream));
+		default:
+			i_fatal("BZ2_bzCompress() failed with %d", ret);
+		}
+	}
+	size -= zs->avail_in;
+
+	zstream->flushed = FALSE;
+	return size;
+}
+
+static int o_stream_bzlib_send_flush(struct bzlib_ostream *zstream, bool final)
+{
+	bz_stream *zs = &zstream->zs;
+	size_t len;
+	bool done = FALSE;
+	int ret;
+
+	i_assert(zs->avail_in == 0);
+
+	if (zstream->flushed) {
+		i_assert(zstream->outbuf_used == 0);
+		return 1;
+	}
+
+	if ((ret = o_stream_flush_parent_if_needed(&zstream->ostream)) <= 0)
+		return ret;
+	if ((ret = o_stream_zlib_send_outbuf(zstream)) <= 0)
+		return ret;
+
+	/* do not attempt to finish the stream early */
+	if (!final)
+		return 1;
+
+	i_assert(zstream->outbuf_used == 0);
+	do {
+		len = sizeof(zstream->outbuf) - zs->avail_out;
+		if (len != 0) {
+			zs->next_out = zstream->outbuf;
+			zs->avail_out = sizeof(zstream->outbuf);
+
+			zstream->outbuf_used = len;
+			if ((ret = o_stream_zlib_send_outbuf(zstream)) <= 0)
+				return ret;
+			if (done)
+				break;
+		}
+
+		ret = BZ2_bzCompress(zs, BZ_FINISH);
+		switch (ret) {
+		case BZ_RUN_OK:
+		case BZ_FLUSH_OK:
+		case BZ_STREAM_END:
+			done = TRUE;
+			break;
+		case BZ_FINISH_OK:
+			break;
+                case BZ_MEM_ERROR:
+                        i_fatal_status(FATAL_OUTOFMEM, "bzip2.write(%s): Out of memory",
+                                       o_stream_get_name(&zstream->ostream.ostream));
+                default:
+                        i_fatal("BZ2_bzCompress() failed with %d", ret);
+		}
+	} while (zs->avail_out != sizeof(zstream->outbuf));
+
+	if (final)
+		zstream->flushed = TRUE;
+	i_assert(zstream->outbuf_used == 0);
+	return 1;
+}
+
+static int o_stream_bzlib_flush(struct ostream_private *stream)
+{
+	struct bzlib_ostream *zstream = (struct bzlib_ostream *)stream;
+	int ret;
+	if ((ret = o_stream_bzlib_send_flush(zstream, stream->finished)) < 0)
+		return -1;
+	else if (ret > 0)
+		return o_stream_flush_parent(stream);
+	return ret;
+}
+
+static size_t
+o_stream_bzlib_get_buffer_used_size(const struct ostream_private *stream)
+{
+	const struct bzlib_ostream *zstream =
+		(const struct bzlib_ostream *)stream;
+
+	/* outbuf has already compressed data that we're trying to send to the
+	   parent stream. We're not including bzlib's internal compression
+	   buffer size. */
+	return (zstream->outbuf_used - zstream->outbuf_offset) +
+		o_stream_get_buffer_used_size(stream->parent);
+}
+
+static size_t
+o_stream_bzlib_get_buffer_avail_size(const struct ostream_private *stream)
+{
+	/* FIXME: not correct - this is counting compressed size, which may be
+	   too larger than uncompressed size in some situations. Fixing would
+	   require some kind of additional buffering. */
+	return o_stream_get_buffer_avail_size(stream->parent);
+}
+
+static ssize_t
+o_stream_bzlib_sendv(struct ostream_private *stream,
+		    const struct const_iovec *iov, unsigned int iov_count)
+{
+	struct bzlib_ostream *zstream = (struct bzlib_ostream *)stream;
+	ssize_t ret, bytes = 0;
+	unsigned int i;
+
+	if ((ret = o_stream_zlib_send_outbuf(zstream)) <= 0) {
+		/* error / we still couldn't flush existing data to
+		   parent stream. */
+		return ret;
+	}
+
+	for (i = 0; i < iov_count; i++) {
+		ret = o_stream_bzlib_send_chunk(zstream, iov[i].iov_base,
+						iov[i].iov_len);
+		if (ret < 0)
+			return -1;
+		bytes += ret;
+		if ((size_t)ret != iov[i].iov_len)
+			break;
+	}
+	stream->ostream.offset += bytes;
+
+	/* avail_in!=0 check is used to detect errors. if it's non-zero here
+	   it simply means we didn't send all the data */
+	zstream->zs.avail_in = 0;
+	return bytes;
+}
+
+struct ostream *o_stream_create_bz2(struct ostream *output, int level)
+{
+	struct bzlib_ostream *zstream;
+	int ret;
+
+	i_assert(level >= 1 && level <= 9);
+
+	zstream = i_new(struct bzlib_ostream, 1);
+	zstream->ostream.sendv = o_stream_bzlib_sendv;
+	zstream->ostream.flush = o_stream_bzlib_flush;
+	zstream->ostream.get_buffer_used_size =
+		o_stream_bzlib_get_buffer_used_size;
+	zstream->ostream.get_buffer_avail_size =
+		o_stream_bzlib_get_buffer_avail_size;
+	zstream->ostream.iostream.close = o_stream_bzlib_close;
+
+	ret = BZ2_bzCompressInit(&zstream->zs, level, 0, 0);
+	switch (ret) {
+	case BZ_OK:
+		break;
+	case BZ_MEM_ERROR:
+		i_fatal_status(FATAL_OUTOFMEM,
+			       "bzlib: Out of memory");
+	case BZ_CONFIG_ERROR:
+		i_fatal("Wrong bzlib library version (broken compilation)");
+	case BZ_PARAM_ERROR:
+		i_fatal("bzlib: Invalid parameters");
+	default:
+		i_fatal("BZ2_bzCompressInit() failed with %d", ret);
+	}
+
+	zstream->zs.next_out = zstream->outbuf;
+	zstream->zs.avail_out = sizeof(zstream->outbuf);
+	return o_stream_create(&zstream->ostream, output,
+			       o_stream_get_fd(output));
+}
+#endif