Add block processing function to compressors

Signed-off-by: David Oberhollenzer <goliath@infraroot.at>

include/comp/compressor.h

@@ -16,6 +16,10 @@ typedef struct compressor_stream_t {
 
 	void (*flush)(struct compressor_stream_t *stream);
 
+	ssize_t (*do_block)(struct compressor_stream_t *stream,
+			    const uint8_t *in, uint8_t *out,
+			    size_t insize, size_t outsize);
+
 	void (*destroy)(struct compressor_stream_t *stream);
 } compressor_stream_t;
 

lib/comp/lzma.c

@@ -92,6 +92,62 @@ static void lzma_flush(compressor_stream_t *base)
 	lzma->action = LZMA_FINISH;
 }
 
+static ssize_t lzma_comp_block(compressor_stream_t *base,
+			       const uint8_t *in, uint8_t *out,
+			       size_t insize, size_t outsize)
+{
+	lzma_filter filters[5];
+	lzma_options_lzma opt;
+	size_t written = 0;
+	lzma_ret ret;
+	(void)base;
+
+	if (lzma_lzma_preset(&opt, LZMA_PRESET_DEFAULT)) {
+		fputs("error initializing LZMA options\n", stderr);
+		return -1;
+	}
+
+	filters[0].id = LZMA_FILTER_LZMA2;
+	filters[0].options = &opt;
+
+	filters[1].id = LZMA_VLI_UNKNOWN;
+	filters[1].options = NULL;
+
+	ret = lzma_stream_buffer_encode(filters, LZMA_CHECK_CRC32, NULL,
+					in, insize, out, &written, outsize);
+
+	if (ret == LZMA_OK)
+		return written;
+
+	if (ret != LZMA_BUF_ERROR) {
+		fputs("lzma block compress failed\n", stderr);
+		return -1;
+	}
+
+	return 0;
+}
+
+static ssize_t lzma_uncomp_block(compressor_stream_t *base,
+				 const uint8_t *in, uint8_t *out,
+				 size_t insize, size_t outsize)
+{
+	uint64_t memlimit = 32 * 1024 * 1024;
+	size_t dest_pos = 0;
+	size_t src_pos = 0;
+	lzma_ret ret;
+	(void)base;
+
+	ret = lzma_stream_buffer_decode(&memlimit, 0, NULL,
+					in, &src_pos, insize,
+					out, &dest_pos, outsize);
+
+	if (ret == LZMA_OK && insize == src_pos)
+		return (ssize_t)dest_pos;
+
+	fputs("lzma block extract failed\n", stderr);
+	return -1;
+}
+
 static void lzma_destroy(compressor_stream_t *base)
 {
 	lzma_stream_t *lzma = (lzma_stream_t *)base;
@@ -134,8 +190,12 @@ static compressor_stream_t *create_stream(bool compress)
 
 		ret = lzma_stream_encoder(&lzma->strm, filters,
 					  LZMA_CHECK_CRC32);
+
+		base->do_block = lzma_comp_block;
 	} else {
 		ret = lzma_stream_decoder(&lzma->strm, UINT64_MAX, 0);
+
+		base->do_block = lzma_uncomp_block;
 	}
 
 	if (ret != LZMA_OK)

lib/comp/none.c

@@ -52,6 +52,19 @@ static ssize_t dummy_read(compressor_stream_t *base,
 	return size;
 }
 
+static ssize_t dummy_do_block(compressor_stream_t *base,
+			      const uint8_t *in, uint8_t *out,
+			      size_t insize, size_t outsize)
+{
+	(void)base;
+
+	if (outsize < insize)
+		return 0;
+
+	memcpy(out, in, insize);
+	return insize;
+}
+
 static void dummy_flush(compressor_stream_t *base)
 {
 	(void)base;
@@ -77,6 +90,7 @@ static compressor_stream_t *create_dummy_stream(compressor_t *cmp)
 	base->write = dummy_write;
 	base->read = dummy_read;
 	base->flush = dummy_flush;
+	base->do_block = dummy_do_block;
 	base->destroy = dummy_destroy;
 	return base;
 }

lib/comp/zlib.c

@@ -112,6 +112,46 @@ static void zlib_destroy(compressor_stream_t *base)
 	free(zlib);
 }
 
+static ssize_t zlib_do_block(compressor_stream_t *base,
+			     const uint8_t *in, uint8_t *out,
+			     size_t insize, size_t outsize)
+{
+	zlib_stream_t *zlib = (zlib_stream_t *)base;
+	int ret;
+
+	if (zlib->compress) {
+		ret = deflateReset(&zlib->strm);
+	} else {
+		ret = inflateReset(&zlib->strm);
+	}
+
+	if (ret != Z_OK) {
+		fputs("resetting zlib stream failed\n", stderr);
+		return -1;
+	}
+
+	zlib->strm.next_in = (void *)in;
+	zlib->strm.avail_in = insize;
+	zlib->strm.next_out = out;
+	zlib->strm.avail_out = outsize;
+
+	if (zlib->compress) {
+		ret = deflate(&zlib->strm, Z_FINISH);
+	} else {
+		ret = inflate(&zlib->strm, Z_FINISH);
+	}
+
+	if (ret == Z_STREAM_END)
+		return (ssize_t)zlib->strm.total_out;
+
+	if (ret != Z_OK) {
+		fputs("zlib block processing failed\n", stderr);
+		return -1;
+	}
+
+	return 0;
+}
+
 static compressor_stream_t *create_stream(bool compress)
 {
 	zlib_stream_t *zlib = calloc(1, sizeof(*zlib));
@@ -130,6 +170,7 @@ static compressor_stream_t *create_stream(bool compress)
 	base->write = zlib_write;
 	base->read = zlib_read;
 	base->flush = zlib_flush;
+	base->do_block = zlib_do_block;
 	base->destroy = zlib_destroy;
 
 	if (compress) {