Add support for uncompressing to iovecs (scatter I/O).

Windows does not have struct iovec defined anywhere,
so we define our own version that's equal to what UNIX
typically has.

The bulk of this patch was contributed by Mohit Aron.

R=jeff


git-svn-id: http://snappy.googlecode.com/svn/trunk@76 03e5f5b5-db94-4691-08a0-1a8bf15f6143

1 files changed, 22 insertions, 0 deletions

diff --git a/snappy.h b/snappy.h
index 03ef6ce..cfd497b 100644
--- a/snappy.h
+++ b/snappy.h
@@ -124,6 +124,28 @@ namespace snappy {
   // returns false if the message is corrupted and could not be decrypted
   bool RawUncompress(Source* compressed, char* uncompressed);
 
+  // Given data in "compressed[0..compressed_length-1]" generated by
+  // calling the Snappy::Compress routine, this routine
+  // stores the uncompressed data to the iovec "iov". The number of physical
+  // buffers in "iov" is given by iov_cnt and their cumulative size
+  // must be at least GetUncompressedLength(compressed). The individual buffers
+  // in "iov" must not overlap with each other.
+  //
+  // returns false if the message is corrupted and could not be decrypted
+  bool RawUncompressToIOVec(const char* compressed, size_t compressed_length,
+                            const struct iovec* iov, size_t iov_cnt);
+
+  // Given data from the byte source 'compressed' generated by calling
+  // the Snappy::Compress routine, this routine stores the uncompressed
+  // data to the iovec "iov". The number of physical
+  // buffers in "iov" is given by iov_cnt and their cumulative size
+  // must be at least GetUncompressedLength(compressed). The individual buffers
+  // in "iov" must not overlap with each other.
+  //
+  // returns false if the message is corrupted and could not be decrypted
+  bool RawUncompressToIOVec(Source* compressed, const struct iovec* iov,
+                            size_t iov_cnt);
+
   // Returns the maximal size of the compressed representation of
   // input data that is "source_bytes" bytes in length;
   size_t MaxCompressedLength(size_t source_bytes);