Add function descriptions to BlockFileIO

encfs/BlockFileIO.cpp

@@ -48,6 +48,12 @@ BlockFileIO::~BlockFileIO() {
   delete[] _cache.data;
 }
 
+/**
+ * Serve a read request for the size of one block or less,
+ * at block-aligned offsets.
+ * Always requests full blocks form the lower layer, truncates the
+ * returned data as neccessary.
+ */
 ssize_t BlockFileIO::cacheReadOneBlock(const IORequest &req) const {
   // we can satisfy the request even if _cache.dataLen is too short, because
   // we always request a full block during reads..
@@ -88,6 +94,13 @@ bool BlockFileIO::cacheWriteOneBlock(const IORequest &req) {
   return ok;
 }
 
+/**
+ * Serve a read request of arbitrary size at an arbitrary offset.
+ * Stitches together multiple blocks to serve large requests, drops
+ * data from the front of the first block if the request is not aligned.
+ * Always requests aligned data of the size of one block or less from the
+ * lower layer.
+ */
 ssize_t BlockFileIO::read(const IORequest &req) const {
   rAssert(_blockSize != 0);
 
@@ -97,7 +110,7 @@ ssize_t BlockFileIO::read(const IORequest &req) const {
 
   if (partialOffset == 0 && req.dataLen <= _blockSize) {
     // read completely within a single block -- can be handled as-is by
-    // readOneBloc().
+    // readOneBlock().
     return cacheReadOneBlock(req);
   } else {
     size_t size = req.dataLen;