Update the code to mostly match the new simpler file format

specification. Simplify things by removing most of the
support for known uncompressed size in most places.
There are some miscellaneous changes here and there too.

The API of liblzma has got many changes and still some
more will be done soon. While most of the code has been
updated, some things are not fixed (the command line tool
will choke with invalid filter chain, if nothing else).

Subblock filter is somewhat broken for now. It will be
updated once the encoded format of the Subblock filter
has been decided.

1 files changed, 43 insertions, 34 deletions

diff --git a/src/liblzma/common/alone_decoder.c b/src/liblzma/common/alone_decoder.c
index 91df5bf2..062f6fab 100644
--- a/src/liblzma/common/alone_decoder.c
+++ b/src/liblzma/common/alone_decoder.c
@@ -32,9 +32,15 @@ struct lzma_coder_s {
 		SEQ_CODE,
 	} sequence;
 
+	/// Position in the header fields
 	size_t pos;
 
-	lzma_options_alone options;
+	/// Uncompressed size decoded from the header
+	lzma_vli uncompressed_size;
+
+	/// Options decoded from the header needed to initialize
+	/// the LZMA decoder
+	lzma_options_lzma options;
 };
 
 
@@ -50,34 +56,39 @@ alone_decode(lzma_coder *coder,
 			&& (coder->sequence == SEQ_CODE || *in_pos < in_size))
 	switch (coder->sequence) {
 	case SEQ_PROPERTIES:
-		if (lzma_lzma_decode_properties(
-				&coder->options.lzma, in[*in_pos]))
-			return LZMA_DATA_ERROR;
+		if (lzma_lzma_decode_properties(&coder->options, in[*in_pos]))
+			return LZMA_FORMAT_ERROR;
 
 		coder->sequence = SEQ_DICTIONARY_SIZE;
 		++*in_pos;
 		break;
 
 	case SEQ_DICTIONARY_SIZE:
-		coder->options.lzma.dictionary_size
+		coder->options.dictionary_size
 				|= (size_t)(in[*in_pos]) << (coder->pos * 8);
 
 		if (++coder->pos == 4) {
-			// A hack to ditch tons of false positives: We allow
-			// only dictionary sizes that are a power of two.
-			// LZMA_Alone didn't create other kinds of files,
-			// although it's not impossible that files with
-			// other dictionary sizes exist. Well, if someone
-			// complains, this will be reconsidered.
-			size_t count = 0;
-			for (size_t i = 0; i < 32; ++i)
-				if (coder->options.lzma.dictionary_size
-						& (UINT32_C(1) << i))
-					++count;
-
-			if (count != 1 || coder->options.lzma.dictionary_size
+			if (coder->options.dictionary_size
+					< LZMA_DICTIONARY_SIZE_MIN
+					|| coder->options.dictionary_size
 					> LZMA_DICTIONARY_SIZE_MAX)
-				return LZMA_DATA_ERROR;
+				return LZMA_FORMAT_ERROR;
+
+			// A hack to ditch tons of false positives: We allow
+			// only dictionary sizes that are 2^n or 2^n + 2^(n-1).
+			// LZMA_Alone created only files with 2^n, but accepts
+			// any dictionary size. If someone complains, this
+			// will be reconsidered.
+			uint32_t d = coder->options.dictionary_size - 1;
+			d |= d >> 2;
+			d |= d >> 3;
+			d |= d >> 4;
+			d |= d >> 8;
+			d |= d >> 16;
+			++d;
+
+			if (d != coder->options.dictionary_size)
+				return LZMA_FORMAT_ERROR;
 
 			coder->pos = 0;
 			coder->sequence = SEQ_UNCOMPRESSED_SIZE;
@@ -87,7 +98,7 @@ alone_decode(lzma_coder *coder,
 		break;
 
 	case SEQ_UNCOMPRESSED_SIZE:
-		coder->options.uncompressed_size
+		coder->uncompressed_size
 				|= (lzma_vli)(in[*in_pos]) << (coder->pos * 8);
 
 		if (++coder->pos == 8) {
@@ -95,11 +106,10 @@ alone_decode(lzma_coder *coder,
 			// if the uncompressed size is known, it must be less
 			// than 256 GiB. Again, if someone complains, this
 			// will be reconsidered.
-			if (coder->options.uncompressed_size
-						!= LZMA_VLI_VALUE_UNKNOWN
-					&& coder->options.uncompressed_size
+			if (coder->uncompressed_size != LZMA_VLI_VALUE_UNKNOWN
+					&& coder->uncompressed_size
 						>= (LZMA_VLI_C(1) << 38))
-				return LZMA_DATA_ERROR;
+				return LZMA_FORMAT_ERROR;
 
 			coder->pos = 0;
 			coder->sequence = SEQ_CODER_INIT;
@@ -113,9 +123,7 @@ alone_decode(lzma_coder *coder,
 		lzma_filter_info filters[2] = {
 			{
 				.init = &lzma_lzma_decoder_init,
-				.options = &coder->options.lzma,
-				.uncompressed_size = coder->options
-						.uncompressed_size,
+				.options = &coder->options,
 			}, {
 				.init = NULL,
 			}
@@ -126,6 +134,10 @@ alone_decode(lzma_coder *coder,
 		if (ret != LZMA_OK)
 			return ret;
 
+		// Use a hack to set the uncompressed size.
+		lzma_lzma_decoder_uncompressed_size(&coder->next,
+				coder->uncompressed_size);
+
 		coder->sequence = SEQ_CODE;
 	}
 
@@ -169,8 +181,8 @@ alone_decoder_init(lzma_next_coder *next, lzma_allocator *allocator)
 
 	next->coder->sequence = SEQ_PROPERTIES;
 	next->coder->pos = 0;
-	next->coder->options.lzma.dictionary_size = 0;
-	next->coder->options.uncompressed_size = 0;
+	next->coder->options.dictionary_size = 0;
+	next->coder->uncompressed_size = 0;
 
 	return LZMA_OK;
 }
@@ -179,17 +191,14 @@ alone_decoder_init(lzma_next_coder *next, lzma_allocator *allocator)
 extern lzma_ret
 lzma_alone_decoder_init(lzma_next_coder *next, lzma_allocator *allocator)
 {
-	// We need to use _init2 because we don't pass any varadic args.
-	lzma_next_coder_init2(next, allocator, alone_decoder_init,
-			alone_decoder_init, allocator);
+	lzma_next_coder_init0(alone_decoder_init, next, allocator);
 }
 
 
 extern LZMA_API lzma_ret
 lzma_alone_decoder(lzma_stream *strm)
 {
-	lzma_next_strm_init2(strm, alone_decoder_init,
-			alone_decoder_init, strm->allocator);
+	lzma_next_strm_init0(strm, alone_decoder_init);
 
 	strm->internal->supported_actions[LZMA_RUN] = true;
 	strm->internal->supported_actions[LZMA_SYNC_FLUSH] = true;