applypatch: Let Apply{BSDiff,Image}Patch accept std::function.

Test: mmma bootable/recovery system/update_engine
Test: recovery_component_test
Change-Id: I93c2caa87bf94a53509bb37f98f2c02bcadb6f5c
diff --git a/applypatch/applypatch.cpp b/applypatch/applypatch.cpp
index 06b8e31..51bf393 100644
--- a/applypatch/applypatch.cpp
+++ b/applypatch/applypatch.cpp
@@ -27,6 +27,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <functional>
 #include <memory>
 #include <string>
 #include <utility>
@@ -42,7 +43,7 @@
 #include "print_sha1.h"
 
 static int LoadPartitionContents(const std::string& filename, FileContents* file);
-static size_t FileSink(const unsigned char* data, size_t len, void* token);
+static size_t FileSink(const unsigned char* data, size_t len, int fd);
 static int GenerateTarget(const FileContents& source_file, const std::unique_ptr<Value>& patch,
                           const std::string& target_filename,
                           const uint8_t target_sha1[SHA_DIGEST_LENGTH], const Value* bonus_data);
@@ -194,7 +195,7 @@
     return -1;
   }
 
-  size_t bytes_written = FileSink(file->data.data(), file->data.size(), &fd);
+  size_t bytes_written = FileSink(file->data.data(), file->data.size(), fd);
   if (bytes_written != file->data.size()) {
     printf("short write of \"%s\" (%zd bytes of %zu): %s\n", filename, bytes_written,
            file->data.size(), strerror(errno));
@@ -433,8 +434,7 @@
     return 0;
 }
 
-static size_t FileSink(const unsigned char* data, size_t len, void* token) {
-  int fd = *static_cast<int*>(token);
+static size_t FileSink(const unsigned char* data, size_t len, int fd) {
   size_t done = 0;
   while (done < len) {
     ssize_t wrote = TEMP_FAILURE_RETRY(ota_write(fd, data + done, len - done));
@@ -447,12 +447,6 @@
   return done;
 }
 
-size_t MemorySink(const unsigned char* data, size_t len, void* token) {
-  std::string* s = static_cast<std::string*>(token);
-  s->append(reinterpret_cast<const char*>(data), len);
-  return len;
-}
-
 // Return the amount of free space (in bytes) on the filesystem
 // containing filename.  filename must exist.  Return -1 on error.
 size_t FreeSpaceForFile(const char* filename) {
@@ -646,9 +640,11 @@
   }
 
   // We store the decoded output in memory.
-  SinkFn sink = MemorySink;
   std::string memory_sink_str;  // Don't need to reserve space.
-  void* token = &memory_sink_str;
+  SinkFn sink = [&memory_sink_str](const unsigned char* data, size_t len) {
+    memory_sink_str.append(reinterpret_cast<const char*>(data), len);
+    return len;
+  };
 
   SHA_CTX ctx;
   SHA1_Init(&ctx);
@@ -656,10 +652,10 @@
   int result;
   if (use_bsdiff) {
     result = ApplyBSDiffPatch(source_file.data.data(), source_file.data.size(), patch.get(), 0,
-                              sink, token, &ctx);
+                              sink, &ctx);
   } else {
     result = ApplyImagePatch(source_file.data.data(), source_file.data.size(), patch.get(), sink,
-                             token, &ctx, bonus_data);
+                             &ctx, bonus_data);
   }
 
   if (result != 0) {
diff --git a/applypatch/bspatch.cpp b/applypatch/bspatch.cpp
index 8ef7a06..f75a2c6 100644
--- a/applypatch/bspatch.cpp
+++ b/applypatch/bspatch.cpp
@@ -24,9 +24,9 @@
 #include <sys/types.h>
 
 #include <bspatch.h>
+#include <openssl/sha.h>
 
 #include "applypatch/applypatch.h"
-#include "openssl/sha.h"
 
 void ShowBSDiffLicense() {
     puts("The bsdiff library used herein is:\n"
@@ -61,9 +61,9 @@
 }
 
 int ApplyBSDiffPatch(const unsigned char* old_data, size_t old_size, const Value* patch,
-                     size_t patch_offset, SinkFn sink, void* token, SHA_CTX* ctx) {
-  auto sha_sink = [&](const uint8_t* data, size_t len) {
-    len = sink(data, len, token);
+                     size_t patch_offset, SinkFn sink, SHA_CTX* ctx) {
+  auto sha_sink = [&sink, &ctx](const uint8_t* data, size_t len) {
+    len = sink(data, len);
     if (ctx) SHA1_Update(ctx, data, len);
     return len;
   };
diff --git a/applypatch/imgpatch.cpp b/applypatch/imgpatch.cpp
index 7a88ffb..7d8b736 100644
--- a/applypatch/imgpatch.cpp
+++ b/applypatch/imgpatch.cpp
@@ -44,10 +44,10 @@
 }
 
 int ApplyImagePatch(const unsigned char* old_data, size_t old_size, const unsigned char* patch_data,
-                    size_t patch_size, SinkFn sink, void* token) {
+                    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);
 }
 
 /*
@@ -57,7 +57,7 @@
  * Return 0 on success.
  */
 int ApplyImagePatch(const unsigned char* old_data, size_t old_size, const Value* patch, SinkFn sink,
-                    void* token, SHA_CTX* ctx, const Value* bonus_data) {
+                    SHA_CTX* ctx, const Value* bonus_data) {
   if (patch->data.size() < 12) {
     printf("patch too short to contain header\n");
     return -1;
@@ -100,7 +100,7 @@
         printf("source data too short\n");
         return -1;
       }
-      ApplyBSDiffPatch(old_data + src_start, src_len, patch, patch_offset, sink, token, ctx);
+      ApplyBSDiffPatch(old_data + src_start, src_len, patch, patch_offset, sink, ctx);
     } else if (type == CHUNK_RAW) {
       const char* raw_header = &patch->data[pos];
       pos += 4;
@@ -116,8 +116,7 @@
         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;
       }
@@ -241,7 +240,7 @@
           ret = deflate(&strm, Z_FINISH);
           size_t have = temp_data.size() - strm.avail_out;
 
-          if (sink(temp_data.data(), have, token) != have) {
+          if (sink(temp_data.data(), have) != have) {
             printf("failed to write %zd compressed bytes to output\n", have);
             return -1;
           }
diff --git a/applypatch/include/applypatch/applypatch.h b/applypatch/include/applypatch/applypatch.h
index 52fb582..da55432 100644
--- a/applypatch/include/applypatch/applypatch.h
+++ b/applypatch/include/applypatch/applypatch.h
@@ -20,6 +20,7 @@
 #include <stdint.h>
 #include <sys/stat.h>
 
+#include <functional>
 #include <memory>
 #include <string>
 #include <vector>
@@ -41,7 +42,7 @@
 // and use it as the source instead.
 #define CACHE_TEMP_SOURCE "/cache/saved.file"
 
-using SinkFn = size_t (*)(const unsigned char*, size_t, void*);
+using SinkFn = std::function<size_t(const unsigned char*, size_t)>;
 
 // applypatch.cpp
 int ShowLicenses();
@@ -67,13 +68,13 @@
 // bspatch.cpp
 void ShowBSDiffLicense();
 int ApplyBSDiffPatch(const unsigned char* old_data, size_t old_size, const Value* patch,
-                     size_t patch_offset, SinkFn sink, void* token, SHA_CTX* ctx);
+                     size_t patch_offset, SinkFn sink, SHA_CTX* ctx);
 int ApplyBSDiffPatchMem(const unsigned char* old_data, size_t old_size, const Value* patch,
                         size_t patch_offset, std::vector<unsigned char>* new_data);
 
 // imgpatch.cpp
 int ApplyImagePatch(const unsigned char* old_data, size_t old_size, const Value* patch, SinkFn sink,
-                    void* token, SHA_CTX* ctx, const Value* bonus_data);
+                    SHA_CTX* ctx, const Value* bonus_data);
 
 // freecache.cpp
 int MakeFreeSpaceOnCache(size_t bytes_needed);
diff --git a/applypatch/include/applypatch/imgpatch.h b/applypatch/include/applypatch/imgpatch.h
index 16e4c4f..07c6609 100644
--- a/applypatch/include/applypatch/imgpatch.h
+++ b/applypatch/include/applypatch/imgpatch.h
@@ -19,9 +19,11 @@
 
 #include <sys/types.h>
 
-using SinkFn = size_t (*)(const unsigned char*, size_t, void*);
+#include <functional>
+
+using SinkFn = std::function<size_t(const unsigned char*, size_t)>;
 
 int ApplyImagePatch(const unsigned char* old_data, size_t old_size, const unsigned char* patch_data,
-                    size_t patch_size, SinkFn sink, void* token);
+                    size_t patch_size, SinkFn sink);
 
 #endif  // _APPLYPATCH_IMGPATCH_H