SimpleCache: merge the first and second stream in one file

net/disk_cache/simple/simple_util.cc

Index: net/disk_cache/simple/simple_util.cc
diff --git a/net/disk_cache/simple/simple_util.cc b/net/disk_cache/simple/simple_util.cc
index 4a89f9b5eb61c61bf01e08104648a15c7482f24c..a881de055283a026dc5d1416c1b6fba32428173b 100644
--- a/net/disk_cache/simple/simple_util.cc
+++ b/net/disk_cache/simple/simple_util.cc
@@ -98,10 +98,24 @@ int64 GetFileSizeFromKeyAndDataSize(const std::string& key, int32 data_size) {
       sizeof(SimpleFileEOF);
 }
 
-int64 GetFileOffsetFromKeyAndDataOffset(const std::string& key,
-                                        int data_offset) {
+int GetFileIndexFromStreamIndex(int stream_index) {
+  return (stream_index == 2) ? 1 : 0;

[pasko, 2013/09/13 19:09:21]

I would prefer to leave stream 2 with the "_2" suffix in the file name. This
backwards-compatibl-ish property helps in some situations like "a
simple_cache_dump_cache" tool that understands both old and new formats while it
seemingly does not have any downsides..

[clamy, 2013/09/16 15:01:17]

File index is being used as an offset in an array of 2 entries, therefore it has
to be strictly smaller than two. We can imagine a function that would convert
the file index in memory to a file name number on disk, but I think it is a bit
too much for an hypothetic backward compatibility.

[pasko, 2013/09/17 11:29:01]

Agreed.

+}
+
+int GetMaximumDataOffset(int file_index, const int data_size[]) {

[pasko, 2013/09/13 19:09:21]

Naming is fun. This name suggests (at least to me) that the function should
return the offset of the maximum byte of the data, while it returns the offset
of first non-data byte (well, counting the 0th EOF record as "data").

So how do we call it? How about GetLastEOFRecordOffset()?

[clamy, 2013/09/16 15:01:17]

Done.

+  if (file_index == 0)
+    return data_size[0] + data_size[1] + sizeof(SimpleFileEOF);
+  return data_size[2];
+}
+
+int64 GetFileOffsetFromDataOffset(const std::string& key,
+                                  int data_offset,
+                                  int index,
+                                  int stream_1_size) {
   const int64 headers_size = sizeof(disk_cache::SimpleFileHeader) + key.size();
-  return headers_size + data_offset;
+  const int64 additional_offset =
+      index == 0 ? stream_1_size + sizeof(SimpleFileEOF) : 0;
+  return headers_size + data_offset + additional_offset;
 }
 
 // TODO(clamy, gavinp): this should go in base