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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:51:24 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:51:24 +0000
commitf7548d6d28c313cf80e6f3ef89aed16a19815df1 (patch)
treea3f6f2a3f247293bee59ecd28e8cd8ceb6ca064a /src/lib-compression/ostream-lz4.c
parentInitial commit. (diff)
downloaddovecot-f7548d6d28c313cf80e6f3ef89aed16a19815df1.tar.xz
dovecot-f7548d6d28c313cf80e6f3ef89aed16a19815df1.zip
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>
Diffstat (limited to 'src/lib-compression/ostream-lz4.c')
-rw-r--r--src/lib-compression/ostream-lz4.c249
1 files changed, 249 insertions, 0 deletions
diff --git a/src/lib-compression/ostream-lz4.c b/src/lib-compression/ostream-lz4.c
new file mode 100644
index 0000000..360f475
--- /dev/null
+++ b/src/lib-compression/ostream-lz4.c
@@ -0,0 +1,249 @@
+/* Copyright (c) 2013-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+
+#ifdef HAVE_LZ4
+
+#include "ostream-private.h"
+#include "ostream-zlib.h"
+#include "iostream-lz4.h"
+#include <lz4.h>
+
+#define CHUNK_SIZE OSTREAM_LZ4_CHUNK_SIZE
+
+struct lz4_ostream {
+ struct ostream_private ostream;
+
+ unsigned char compressbuf[CHUNK_SIZE];
+ unsigned int compressbuf_offset;
+
+ /* chunk size, followed by compressed data */
+ unsigned char outbuf[IOSTREAM_LZ4_CHUNK_PREFIX_LEN +
+ LZ4_COMPRESSBOUND(CHUNK_SIZE)];
+ unsigned int outbuf_offset, outbuf_used;
+};
+
+/* There is no actual compression level in LZ4, so for legacy
+ reasons we allow 1-9 to avoid breaking anyone's config. */
+int compression_get_min_level_lz4(void)
+{
+ return 1;
+}
+
+int compression_get_default_level_lz4(void)
+{
+ return 1;
+}
+
+int compression_get_max_level_lz4(void)
+{
+ return 9;
+}
+
+static void o_stream_lz4_close(struct iostream_private *stream,
+ bool close_parent)
+{
+ struct lz4_ostream *zstream = (struct lz4_ostream *)stream;
+
+ if (close_parent)
+ o_stream_close(zstream->ostream.parent);
+}
+
+static int o_stream_lz4_send_outbuf(struct lz4_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 int o_stream_lz4_compress(struct lz4_ostream *zstream)
+{
+ uint32_t chunk_size;
+ int ret;
+
+ if (zstream->compressbuf_offset == 0)
+ return 1;
+ if ((ret = o_stream_lz4_send_outbuf(zstream)) <= 0)
+ return ret;
+
+ i_assert(zstream->outbuf_offset == 0);
+ i_assert(zstream->outbuf_used == 0);
+
+#if defined(HAVE_LZ4_COMPRESS_DEFAULT)
+ int max_dest_size = LZ4_compressBound(zstream->compressbuf_offset);
+ i_assert(max_dest_size >= 0);
+ if (max_dest_size == 0) {
+ io_stream_set_error(&zstream->ostream.iostream,
+ "lz4-compress: input size %u too large (> %u)",
+ zstream->compressbuf_offset, LZ4_MAX_INPUT_SIZE);
+ zstream->ostream.ostream.stream_errno = EINVAL;
+ return -1;
+ }
+ ret = LZ4_compress_default((void *)zstream->compressbuf,
+ (void *)(zstream->outbuf +
+ IOSTREAM_LZ4_CHUNK_PREFIX_LEN),
+ zstream->compressbuf_offset,
+ max_dest_size);
+#else
+ ret = LZ4_compress((void *)zstream->compressbuf,
+ (void *)(zstream->outbuf +
+ IOSTREAM_LZ4_CHUNK_PREFIX_LEN),
+ zstream->compressbuf_offset);
+#endif /* defined(HAVE_LZ4_COMPRESS_DEFAULT) */
+ i_assert(ret > 0 && (unsigned int)ret <= sizeof(zstream->outbuf) -
+ IOSTREAM_LZ4_CHUNK_PREFIX_LEN);
+ zstream->outbuf_used = IOSTREAM_LZ4_CHUNK_PREFIX_LEN + ret;
+ chunk_size = zstream->outbuf_used - IOSTREAM_LZ4_CHUNK_PREFIX_LEN;
+ zstream->outbuf[0] = (chunk_size & 0xff000000) >> 24;
+ zstream->outbuf[1] = (chunk_size & 0x00ff0000) >> 16;
+ zstream->outbuf[2] = (chunk_size & 0x0000ff00) >> 8;
+ zstream->outbuf[3] = (chunk_size & 0x000000ff);
+ zstream->compressbuf_offset = 0;
+ return 1;
+}
+
+static ssize_t
+o_stream_lz4_send_chunk(struct lz4_ostream *zstream,
+ const void *data, size_t size)
+{
+ size_t max_size;
+ ssize_t added_bytes = 0;
+ int ret;
+
+ i_assert(zstream->outbuf_used == 0);
+
+ do {
+ max_size = I_MIN(size, sizeof(zstream->compressbuf) -
+ zstream->compressbuf_offset);
+ memcpy(zstream->compressbuf + zstream->compressbuf_offset,
+ data, max_size);
+ zstream->compressbuf_offset += max_size;
+
+ data = CONST_PTR_OFFSET(data, max_size);
+ size -= max_size;
+ added_bytes += max_size;
+
+ if (zstream->compressbuf_offset == sizeof(zstream->compressbuf)) {
+ ret = o_stream_lz4_compress(zstream);
+ if (ret <= 0)
+ return added_bytes != 0 ? added_bytes : ret;
+ }
+ } while (size > 0);
+
+ return added_bytes;
+}
+
+static int o_stream_lz4_flush(struct ostream_private *stream)
+{
+ struct lz4_ostream *zstream = (struct lz4_ostream *)stream;
+
+ if (o_stream_lz4_compress(zstream) < 0)
+ return -1;
+ if (o_stream_lz4_send_outbuf(zstream) < 0)
+ return -1;
+
+ return o_stream_flush_parent(stream);
+}
+
+static size_t
+o_stream_lz4_get_buffer_used_size(const struct ostream_private *stream)
+{
+ const struct lz4_ostream *zstream =
+ (const struct lz4_ostream *)stream;
+
+ /* outbuf has already compressed data that we're trying to send to the
+ parent stream. compressbuf isn't included in the return value,
+ because it needs to be filled up or flushed. */
+ return (zstream->outbuf_used - zstream->outbuf_offset) +
+ o_stream_get_buffer_used_size(stream->parent);
+}
+
+static size_t
+o_stream_lz4_get_buffer_avail_size(const struct ostream_private *stream)
+{
+ const struct lz4_ostream *zstream =
+ (const struct lz4_ostream *)stream;
+
+ /* We're only guaranteed to accept data to compressbuf. The parent
+ stream might have space, but since compressed data gets written
+ there it's not really known how much we can actually write there. */
+ return sizeof(zstream->compressbuf) - zstream->compressbuf_offset;
+}
+
+static ssize_t
+o_stream_lz4_sendv(struct ostream_private *stream,
+ const struct const_iovec *iov, unsigned int iov_count)
+{
+ struct lz4_ostream *zstream = (struct lz4_ostream *)stream;
+ ssize_t ret, bytes = 0;
+ unsigned int i;
+
+ if ((ret = o_stream_lz4_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_lz4_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;
+ return bytes;
+}
+
+struct ostream *o_stream_create_lz4(struct ostream *output, int level)
+{
+ struct iostream_lz4_header *hdr;
+ struct lz4_ostream *zstream;
+
+ i_assert(level >= 1 && level <= 9);
+
+ zstream = i_new(struct lz4_ostream, 1);
+ zstream->ostream.sendv = o_stream_lz4_sendv;
+ zstream->ostream.flush = o_stream_lz4_flush;
+ zstream->ostream.get_buffer_used_size =
+ o_stream_lz4_get_buffer_used_size;
+ zstream->ostream.get_buffer_avail_size =
+ o_stream_lz4_get_buffer_avail_size;
+ zstream->ostream.iostream.close = o_stream_lz4_close;
+
+ i_assert(sizeof(zstream->outbuf) >= sizeof(*hdr));
+ hdr = (void *)zstream->outbuf;
+ memcpy(hdr->magic, IOSTREAM_LZ4_MAGIC, sizeof(hdr->magic));
+ hdr->max_uncompressed_chunk_size[0] =
+ (OSTREAM_LZ4_CHUNK_SIZE & 0xff000000) >> 24;
+ hdr->max_uncompressed_chunk_size[1] =
+ (OSTREAM_LZ4_CHUNK_SIZE & 0x00ff0000) >> 16;
+ hdr->max_uncompressed_chunk_size[2] =
+ (OSTREAM_LZ4_CHUNK_SIZE & 0x0000ff00) >> 8;
+ hdr->max_uncompressed_chunk_size[3] =
+ (OSTREAM_LZ4_CHUNK_SIZE & 0x000000ff);
+ zstream->outbuf_used = sizeof(*hdr);
+ return o_stream_create(&zstream->ostream, output,
+ o_stream_get_fd(output));
+}
+#endif