Produce ZERO operations directly for zero blocks. am: 2560c5430a am: c0da40b2df

am: 84975ec731

Change-Id: I72161513928205b7b09bcc247ee537e473a27a35

1 files changed, 28 insertions, 14 deletions

diff --git a/payload_generator/delta_diff_utils.cc b/payload_generator/delta_diff_utils.cc
index c0962bf9..4ee1024f 100644
--- a/payload_generator/delta_diff_utils.cc
+++ b/payload_generator/delta_diff_utils.cc
@@ -493,30 +493,44 @@ bool DeltaMovedAndZeroBlocks(vector<AnnotatedOperation>* aops,
       old_blocks_map_it->second.pop_back();
   }
 
+  if (chunk_blocks == -1)
+    chunk_blocks = new_num_blocks;
+
   // Produce operations for the zero blocks split per output extent.
-  // TODO(deymo): Produce ZERO operations instead of calling DeltaReadFile().
   size_t num_ops = aops->size();
   new_visited_blocks->AddExtents(new_zeros);
   for (const Extent& extent : new_zeros) {
-    TEST_AND_RETURN_FALSE(DeltaReadFile(aops,
-                                        "",
-                                        new_part,
-                                        vector<Extent>(),        // old_extents
-                                        vector<Extent>{extent},  // new_extents
-                                        {},                      // old_deflates
-                                        {},                      // new_deflates
-                                        "<zeros>",
-                                        chunk_blocks,
-                                        version,
-                                        blob_file));
+    if (version.OperationAllowed(InstallOperation::ZERO)) {
+      for (uint64_t offset = 0; offset < extent.num_blocks();
+           offset += chunk_blocks) {
+        uint64_t num_blocks =
+            std::min(static_cast<uint64_t>(extent.num_blocks()) - offset,
+                     static_cast<uint64_t>(chunk_blocks));
+        InstallOperation operation;
+        operation.set_type(InstallOperation::ZERO);
+        *(operation.add_dst_extents()) =
+            ExtentForRange(extent.start_block() + offset, num_blocks);
+        aops->push_back({.name = "<zeros>", .op = operation});
+      }
+    } else {
+      TEST_AND_RETURN_FALSE(DeltaReadFile(aops,
+                                          "",
+                                          new_part,
+                                          {},        // old_extents
+                                          {extent},  // new_extents
+                                          {},        // old_deflates
+                                          {},        // new_deflates
+                                          "<zeros>",
+                                          chunk_blocks,
+                                          version,
+                                          blob_file));
+    }
   }
   LOG(INFO) << "Produced " << (aops->size() - num_ops) << " operations for "
             << utils::BlocksInExtents(new_zeros) << " zeroed blocks";
 
   // Produce MOVE/SOURCE_COPY operations for the moved blocks.
   num_ops = aops->size();
-  if (chunk_blocks == -1)
-    chunk_blocks = new_num_blocks;
   uint64_t used_blocks = 0;
   old_visited_blocks->AddExtents(old_identical_blocks);
   new_visited_blocks->AddExtents(new_identical_blocks);