liblzma: Add the forgotten lzma_lzma2_block_size().

This should have been in 5eefc0086d24a65e136352f8c1d19cefb0cbac7a.

2 files changed, 12 insertions, 0 deletions

diff --git a/src/liblzma/lzma/lzma2_encoder.c b/src/liblzma/lzma/lzma2_encoder.c
index e734bc5..28442c3 100644
--- a/src/liblzma/lzma/lzma2_encoder.c
+++ b/src/liblzma/lzma/lzma2_encoder.c
@@ -391,3 +391,13 @@ lzma_lzma2_props_encode(const void *options, uint8_t *out)
 
 	return LZMA_OK;
 }
+
+
+extern uint64_t
+lzma_lzma2_block_size(const void *options)
+{
+	const lzma_options_lzma *const opt = options;
+
+	// Use at least 1 MiB to keep compression ratio better.
+	return my_max((uint64_t)(opt->dict_size) * 3, UINT64_C(1) << 20);
+}
diff --git a/src/liblzma/lzma/lzma2_encoder.h b/src/liblzma/lzma/lzma2_encoder.h
index ca19ef4..1288136 100644
--- a/src/liblzma/lzma/lzma2_encoder.h
+++ b/src/liblzma/lzma/lzma2_encoder.h
@@ -38,4 +38,6 @@ extern uint64_t lzma_lzma2_encoder_memusage(const void *options);
 
 extern lzma_ret lzma_lzma2_props_encode(const void *options, uint8_t *out);
 
+extern uint64_t lzma_lzma2_block_size(const void *options);
+
 #endif