commit b379d19c05c5128a7fa45b72dbe74a764d143b98
author Amin Hassani <ahassani@google.com> Wed Dec 06 15:31:17 2017 -0800
committer Amin Hassani <ahassani@google.com> Mon Feb 05 12:53:18 2018 -0800
tree 4401a36d4174b68dfeff004d85f4ff3a1f45e5da
parent 4e13cf4743d5c02dec7030c71a3c7e2fa8da7aa8

Restructure hash calculation in delta_performer

This patch moves DeltaPerformer::CalculateAndValidateHash to
fd_utils::ReadAndHashExtents and cleans up the code. It also adds
unittests for ReadAndHashExtents.

Bug: None
Test: unittest pass

Change-Id: I297cf79ef38a7495d5bcc0e6516a1ca783e505ea
Signed-off-by: Amin Hassani <ahassani@google.com>

payload_consumer/delta_performer.cc

diff --git a/payload_consumer/delta_performer.cc b/payload_consumer/delta_performer.cc
index 6540675..a392b40 100644
--- a/payload_consumer/delta_performer.cc
+++ b/payload_consumer/delta_performer.cc
@@ -1207,28 +1207,6 @@
   return true;
 }
 
-bool DeltaPerformer::CalculateAndValidateSourceHash(
-    const InstallOperation& operation, ErrorCode* error) {
-  const uint64_t kMaxBlocksToRead = 256;  // 1MB if block size is 4KB
-  auto total_blocks = utils::BlocksInExtents(operation.src_extents());
-  brillo::Blob buf(std::min(kMaxBlocksToRead, total_blocks) * block_size_);
-  DirectExtentReader reader;
-  TEST_AND_RETURN_FALSE(
-      reader.Init(source_fd_, operation.src_extents(), block_size_));
-  HashCalculator source_hasher;
-  while (total_blocks > 0) {
-    auto read_blocks = std::min(total_blocks, kMaxBlocksToRead);
-    TEST_AND_RETURN_FALSE(reader.Read(buf.data(), read_blocks * block_size_));
-    TEST_AND_RETURN_FALSE(
-        source_hasher.Update(buf.data(), read_blocks * block_size_));
-    total_blocks -= read_blocks;
-  }
-  TEST_AND_RETURN_FALSE(source_hasher.Finalize());
-  TEST_AND_RETURN_FALSE(ValidateSourceHash(
-      source_hasher.raw_hash(), operation, source_fd_, error));
-  return true;
-}
-
 namespace {
 
 class BsdiffExtentFile : public bsdiff::FileInterface {
@@ -1309,7 +1287,11 @@
     TEST_AND_RETURN_FALSE(operation.dst_length() % block_size_ == 0);
 
   if (operation.has_src_sha256_hash()) {
-    TEST_AND_RETURN_FALSE(CalculateAndValidateSourceHash(operation, error));
+    brillo::Blob source_hash;
+    TEST_AND_RETURN_FALSE(fd_utils::ReadAndHashExtents(
+        source_fd_, operation.src_extents(), block_size_, &source_hash));
+    TEST_AND_RETURN_FALSE(
+        ValidateSourceHash(source_hash, operation, source_fd_, error));
   }
 
   auto reader = std::make_unique<DirectExtentReader>();
@@ -1422,7 +1404,11 @@
   TEST_AND_RETURN_FALSE(buffer_.size() >= operation.data_length());
 
   if (operation.has_src_sha256_hash()) {
-    TEST_AND_RETURN_FALSE(CalculateAndValidateSourceHash(operation, error));
+    brillo::Blob source_hash;
+    TEST_AND_RETURN_FALSE(fd_utils::ReadAndHashExtents(
+        source_fd_, operation.src_extents(), block_size_, &source_hash));
+    TEST_AND_RETURN_FALSE(
+        ValidateSourceHash(source_hash, operation, source_fd_, error));
   }
 
   auto reader = std::make_unique<DirectExtentReader>();