1 files changed, 100 insertions, 69 deletions

diff --git a/applypatch/imgpatch.cpp b/applypatch/imgpatch.cpp
index adcc61fd6..df75f98d4 100644
--- a/applypatch/imgpatch.cpp
+++ b/applypatch/imgpatch.cpp
@@ -26,12 +26,14 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
+#include <memory>
 #include <string>
 #include <vector>
 
+#include <android-base/logging.h>
+#include <android-base/memory.h>
 #include <applypatch/applypatch.h>
 #include <applypatch/imgdiff.h>
-#include <android-base/memory.h>
 #include <openssl/sha.h>
 #include <zlib.h>
 
@@ -43,12 +45,91 @@ static inline int32_t Read4(const void *address) {
   return android::base::get_unaligned<int32_t>(address);
 }
 
-int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
-                    const unsigned char* patch_data, ssize_t patch_size,
-                    SinkFn sink, void* token) {
+// This function is a wrapper of ApplyBSDiffPatch(). It has a custom sink function to deflate the
+// patched data and stream the deflated data to output.
+static bool ApplyBSDiffPatchAndStreamOutput(const uint8_t* src_data, size_t src_len,
+                                            const Value* patch, size_t patch_offset,
+                                            const char* deflate_header, SinkFn sink, SHA_CTX* ctx) {
+  size_t expected_target_length = static_cast<size_t>(Read8(deflate_header + 32));
+  int level = Read4(deflate_header + 40);
+  int method = Read4(deflate_header + 44);
+  int window_bits = Read4(deflate_header + 48);
+  int mem_level = Read4(deflate_header + 52);
+  int strategy = Read4(deflate_header + 56);
+
+  std::unique_ptr<z_stream, decltype(&deflateEnd)> strm(new z_stream(), deflateEnd);
+  strm->zalloc = Z_NULL;
+  strm->zfree = Z_NULL;
+  strm->opaque = Z_NULL;
+  strm->avail_in = 0;
+  strm->next_in = nullptr;
+  int ret = deflateInit2(strm.get(), level, method, window_bits, mem_level, strategy);
+  if (ret != Z_OK) {
+    LOG(ERROR) << "Failed to init uncompressed data deflation: " << ret;
+    return false;
+  }
+
+  // Define a custom sink wrapper that feeds to bspatch. It deflates the available patch data on
+  // the fly and outputs the compressed data to the given sink.
+  size_t actual_target_length = 0;
+  size_t total_written = 0;
+  static constexpr size_t buffer_size = 32768;
+  auto compression_sink = [&](const uint8_t* data, size_t len) -> size_t {
+    // The input patch length for an update never exceeds INT_MAX.
+    strm->avail_in = len;
+    strm->next_in = data;
+    do {
+      std::vector<uint8_t> buffer(buffer_size);
+      strm->avail_out = buffer_size;
+      strm->next_out = buffer.data();
+      if (actual_target_length + len < expected_target_length) {
+        ret = deflate(strm.get(), Z_NO_FLUSH);
+      } else {
+        ret = deflate(strm.get(), Z_FINISH);
+      }
+      if (ret != Z_OK && ret != Z_STREAM_END) {
+        LOG(ERROR) << "Failed to deflate stream: " << ret;
+        // zero length indicates an error in the sink function of bspatch().
+        return 0;
+      }
+
+      size_t have = buffer_size - strm->avail_out;
+      total_written += have;
+      if (sink(buffer.data(), have) != have) {
+        LOG(ERROR) << "Failed to write " << have << " compressed bytes to output.";
+        return 0;
+      }
+      if (ctx) SHA1_Update(ctx, buffer.data(), have);
+    } while ((strm->avail_in != 0 || strm->avail_out == 0) && ret != Z_STREAM_END);
+
+    actual_target_length += len;
+    return len;
+  };
+
+  if (ApplyBSDiffPatch(src_data, src_len, patch, patch_offset, compression_sink, nullptr) != 0) {
+    return false;
+  }
+
+  if (ret != Z_STREAM_END) {
+    LOG(ERROR) << "ret is expected to be Z_STREAM_END, but it's " << ret;
+    return false;
+  }
+
+  if (expected_target_length != actual_target_length) {
+    LOG(ERROR) << "target length is expected to be " << expected_target_length << ", but it's "
+               << actual_target_length;
+    return false;
+  }
+  LOG(DEBUG) << "bspatch writes " << total_written << " bytes in total to streaming output.";
+
+  return true;
+}
+
+int ApplyImagePatch(const unsigned char* old_data, size_t old_size, const unsigned char* patch_data,
+                    size_t patch_size, SinkFn sink) {
   Value patch(VAL_BLOB, std::string(reinterpret_cast<const char*>(patch_data), patch_size));
 
-  return ApplyImagePatch(old_data, old_size, &patch, sink, token, nullptr, nullptr);
+  return ApplyImagePatch(old_data, old_size, &patch, sink, nullptr, nullptr);
 }
 
 /*
@@ -57,8 +138,8 @@ int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
  * file, and update the SHA context with the output data as well.
  * Return 0 on success.
  */
-int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size, const Value* patch,
-                    SinkFn sink, void* token, SHA_CTX* ctx, const Value* bonus_data) {
+int ApplyImagePatch(const unsigned char* old_data, size_t old_size, const Value* patch, SinkFn sink,
+                    SHA_CTX* ctx, const Value* bonus_data) {
   if (patch->data.size() < 12) {
     printf("patch too short to contain header\n");
     return -1;
@@ -97,11 +178,14 @@ int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size, const Value
       size_t src_len = static_cast<size_t>(Read8(normal_header + 8));
       size_t patch_offset = static_cast<size_t>(Read8(normal_header + 16));
 
-      if (src_start + src_len > static_cast<size_t>(old_size)) {
+      if (src_start + src_len > old_size) {
         printf("source data too short\n");
         return -1;
       }
-      ApplyBSDiffPatch(old_data + src_start, src_len, patch, patch_offset, sink, token, ctx);
+      if (ApplyBSDiffPatch(old_data + src_start, src_len, patch, patch_offset, sink, ctx) != 0) {
+        printf("Failed to apply bsdiff patch.\n");
+        return -1;
+      }
     } else if (type == CHUNK_RAW) {
       const char* raw_header = &patch->data[pos];
       pos += 4;
@@ -110,15 +194,14 @@ int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size, const Value
         return -1;
       }
 
-      ssize_t data_len = Read4(raw_header);
+      size_t data_len = static_cast<size_t>(Read4(raw_header));
 
       if (pos + data_len > patch->data.size()) {
         printf("failed to read chunk %d raw data\n", i);
         return -1;
       }
       if (ctx) SHA1_Update(ctx, &patch->data[pos], data_len);
-      if (sink(reinterpret_cast<const unsigned char*>(&patch->data[pos]), data_len, token) !=
-          data_len) {
+      if (sink(reinterpret_cast<const unsigned char*>(&patch->data[pos]), data_len) != data_len) {
         printf("failed to write chunk %d raw data\n", i);
         return -1;
       }
@@ -136,14 +219,8 @@ int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size, const Value
       size_t src_len = static_cast<size_t>(Read8(deflate_header + 8));
       size_t patch_offset = static_cast<size_t>(Read8(deflate_header + 16));
       size_t expanded_len = static_cast<size_t>(Read8(deflate_header + 24));
-      size_t target_len = static_cast<size_t>(Read8(deflate_header + 32));
-      int level = Read4(deflate_header + 40);
-      int method = Read4(deflate_header + 44);
-      int windowBits = Read4(deflate_header + 48);
-      int memLevel = Read4(deflate_header + 52);
-      int strategy = Read4(deflate_header + 56);
-
-      if (src_start + src_len > static_cast<size_t>(old_size)) {
+
+      if (src_start + src_len > old_size) {
         printf("source data too short\n");
         return -1;
       }
@@ -198,58 +275,12 @@ int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size, const Value
         }
       }
 
-      // Next, apply the bsdiff patch (in memory) to the uncompressed data.
-      std::vector<unsigned char> uncompressed_target_data;
-      // TODO(senj): Remove the only usage of ApplyBSDiffPatchMem here,
-      // replace it with ApplyBSDiffPatch with a custom sink function that
-      // wraps the given sink function to stream output to save memory.
-      if (ApplyBSDiffPatchMem(expanded_source.data(), expanded_len, patch, patch_offset,
-                              &uncompressed_target_data) != 0) {
-        return -1;
-      }
-      if (uncompressed_target_data.size() != target_len) {
-        printf("expected target len to be %zu, but it's %zu\n", target_len,
-               uncompressed_target_data.size());
+      if (!ApplyBSDiffPatchAndStreamOutput(expanded_source.data(), expanded_len, patch,
+                                           patch_offset, deflate_header, sink, ctx)) {
+        LOG(ERROR) << "Fail to apply streaming bspatch.";
         return -1;
       }
 
-      // Now compress the target data and append it to the output.
-
-      // we're done with the expanded_source data buffer, so we'll
-      // reuse that memory to receive the output of deflate.
-      if (expanded_source.size() < 32768U) {
-        expanded_source.resize(32768U);
-      }
-
-      {
-        std::vector<unsigned char>& temp_data = expanded_source;
-
-        // now the deflate stream
-        z_stream strm;
-        strm.zalloc = Z_NULL;
-        strm.zfree = Z_NULL;
-        strm.opaque = Z_NULL;
-        strm.avail_in = uncompressed_target_data.size();
-        strm.next_in = uncompressed_target_data.data();
-        int ret = deflateInit2(&strm, level, method, windowBits, memLevel, strategy);
-        if (ret != Z_OK) {
-          printf("failed to init uncompressed data deflation: %d\n", ret);
-          return -1;
-        }
-        do {
-          strm.avail_out = temp_data.size();
-          strm.next_out = temp_data.data();
-          ret = deflate(&strm, Z_FINISH);
-          ssize_t have = temp_data.size() - strm.avail_out;
-
-          if (sink(temp_data.data(), have, token) != have) {
-            printf("failed to write %zd compressed bytes to output\n", have);
-            return -1;
-          }
-          if (ctx) SHA1_Update(ctx, temp_data.data(), have);
-        } while (ret != Z_STREAM_END);
-        deflateEnd(&strm);
-      }
     } else {
       printf("patch chunk %d is unknown type %d\n", i, type);
       return -1;