From 214a5e917ee0e1b858f069e6a68af32d0b09b22c Mon Sep 17 00:00:00 2001
From: David Oberhollenzer <goliath@infraroot.at>
Date: Wed, 17 Apr 2019 23:56:39 +0200
Subject: [PATCH] Add a way to pass options to compressors

Currently only used by lzma compressor to set the dictionary size.

Signed-off-by: David Oberhollenzer <goliath@infraroot.at>
---
 include/comp/compressor.h |  3 ++-
 lib/comp/lzma.c           | 18 +++++++++++++-----
 lib/comp/none.c           | 12 +++++++++---
 lib/comp/zlib.c           |  4 ++--
 lib/pkg/pkgwriter.c       |  4 ++--
 5 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/include/comp/compressor.h b/include/comp/compressor.h
index 34bc586..ef6c16e 100644
--- a/include/comp/compressor.h
+++ b/include/comp/compressor.h
@@ -28,7 +28,8 @@ typedef struct compressor_t {
 	const char *name;
 	PKG_COMPRESSION id;
 
-	compressor_stream_t *(*compression_stream)(struct compressor_t *cmp);
+	compressor_stream_t *(*compression_stream)(struct compressor_t *cmp,
+						   void *options);
 
 	compressor_stream_t *(*uncompression_stream)(struct compressor_t *cmp);
 } compressor_t;
diff --git a/lib/comp/lzma.c b/lib/comp/lzma.c
index 7fbb343..2624f2c 100644
--- a/lib/comp/lzma.c
+++ b/lib/comp/lzma.c
@@ -17,6 +17,7 @@ typedef struct {
 	int used;
 	bool eof;
 	bool error;
+	size_t dict_size;
 } lzma_stream_t;
 
 static ssize_t lzma_write(compressor_stream_t *base,
@@ -96,17 +97,20 @@ static ssize_t lzma_comp_block(compressor_stream_t *base,
 			       const uint8_t *in, uint8_t *out,
 			       size_t insize, size_t outsize)
 {
+	lzma_stream_t *lzma = (lzma_stream_t *)base;
 	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;
 	}
 
+	if (lzma->dict_size)
+		opt.dict_size = lzma->dict_size;
+
 	filters[0].id = LZMA_FILTER_LZMA2;
 	filters[0].options = &opt;
 
@@ -156,7 +160,7 @@ static void lzma_destroy(compressor_stream_t *base)
 	free(lzma);
 }
 
-static compressor_stream_t *create_stream(bool compress)
+static compressor_stream_t *create_stream(bool compress, size_t dict_size)
 {
 	lzma_stream_t *lzma = calloc(1, sizeof(*lzma));
 	compressor_stream_t *base;
@@ -169,6 +173,7 @@ static compressor_stream_t *create_stream(bool compress)
 	}
 
 	lzma->action = LZMA_RUN;
+	lzma->dict_size = dict_size;
 
 	base = (compressor_stream_t *)lzma;
 	base->write = lzma_write;
@@ -182,6 +187,9 @@ static compressor_stream_t *create_stream(bool compress)
 		if (lzma_lzma_preset(&opt_lzma2, LZMA_PRESET_DEFAULT))
 			goto fail;
 
+		if (dict_size)
+			opt_lzma2.dict_size = dict_size;
+
 		filters[0].id = LZMA_FILTER_LZMA2;
 		filters[0].options = &opt_lzma2;
 
@@ -208,16 +216,16 @@ fail:
 	return NULL;
 }
 
-static compressor_stream_t *lzma_compress(compressor_t *cmp)
+static compressor_stream_t *lzma_compress(compressor_t *cmp, void *options)
 {
 	(void)cmp;
-	return create_stream(true);
+	return create_stream(true, options == NULL ? 0 : *((size_t *)options));
 }
 
 static compressor_stream_t *lzma_uncompress(compressor_t *cmp)
 {
 	(void)cmp;
-	return create_stream(false);
+	return create_stream(false, 0);
 }
 
 compressor_t comp_lzma = {
diff --git a/lib/comp/none.c b/lib/comp/none.c
index 6d54e59..539ba72 100644
--- a/lib/comp/none.c
+++ b/lib/comp/none.c
@@ -75,11 +75,12 @@ static void dummy_destroy(compressor_stream_t *base)
 	free(base);
 }
 
-static compressor_stream_t *create_dummy_stream(compressor_t *cmp)
+static compressor_stream_t *create_dummy_stream(compressor_t *cmp,
+						void *options)
 {
 	dummy_stream_t *dummy = calloc(1, sizeof(*dummy));
 	compressor_stream_t *base;
-	(void)cmp;
+	(void)cmp; (void)options;
 
 	if (dummy == NULL) {
 		perror("creating dummy compressor stream");
@@ -95,9 +96,14 @@ static compressor_stream_t *create_dummy_stream(compressor_t *cmp)
 	return base;
 }
 
+static compressor_stream_t *create_dummy_uncompressor(compressor_t *cmp)
+{
+	return create_dummy_stream(cmp, NULL);
+}
+
 compressor_t comp_none = {
 	.name = "none",
 	.id = PKG_COMPRESSION_NONE,
 	.compression_stream = create_dummy_stream,
-	.uncompression_stream = create_dummy_stream,
+	.uncompression_stream = create_dummy_uncompressor,
 };
diff --git a/lib/comp/zlib.c b/lib/comp/zlib.c
index 7f54d2b..6f7c2db 100644
--- a/lib/comp/zlib.c
+++ b/lib/comp/zlib.c
@@ -188,9 +188,9 @@ static compressor_stream_t *create_stream(bool compress)
 	return base;
 }
 
-static compressor_stream_t *zlib_compress(compressor_t *cmp)
+static compressor_stream_t *zlib_compress(compressor_t *cmp, void *options)
 {
-	(void)cmp;
+	(void)cmp; (void)options;
 	return create_stream(true);
 }
 
diff --git a/lib/pkg/pkgwriter.c b/lib/pkg/pkgwriter.c
index 1781f1f..a4bd556 100644
--- a/lib/pkg/pkgwriter.c
+++ b/lib/pkg/pkgwriter.c
@@ -96,7 +96,7 @@ pkg_writer_t *pkg_writer_open(const char *path, bool force)
 		return NULL;
 	}
 
-	wr->stream = cmp->compression_stream(cmp);
+	wr->stream = cmp->compression_stream(cmp, NULL);
 	if (wr->stream == NULL) {
 		fputs("error creating compressor stream for package header\n",
 		      stderr);
@@ -153,7 +153,7 @@ int pkg_writer_start_record(pkg_writer_t *wr, uint32_t magic,
 	if (write_header(wr))
 		return -1;
 
-	wr->stream = cmp->compression_stream(cmp);
+	wr->stream = cmp->compression_stream(cmp, NULL);
 	if (wr->stream == NULL)
 		return -1;