Remove the FD parameter from FuseDataProvider ctor.

This leaves the FD implementation details to subclasses. In particular,
it allows minadbd to do additional works with the FD after sideloading.

Bug: 128415917
Test: atest recovery_component_test
Test: atest minadbd_test
Test: Sideload package on taimen.
Change-Id: I106bbaad05201227bbc5fe28890bbbb06fdcb67e

fuse_sideload/include/fuse_provider.h

@@ -25,8 +25,8 @@
 // This is the base class to read data from source and provide the data to FUSE.
 class FuseDataProvider {
  public:
-  FuseDataProvider(android::base::unique_fd&& fd, uint64_t file_size, uint32_t block_size)
-      : fd_(std::move(fd)), file_size_(file_size), fuse_block_size_(block_size) {}
+  FuseDataProvider(uint64_t file_size, uint32_t block_size)
+      : file_size_(file_size), fuse_block_size_(block_size) {}
 
   virtual ~FuseDataProvider() = default;
 
@@ -37,21 +37,15 @@ class FuseDataProvider {
     return fuse_block_size_;
   }
 
-  bool Valid() const {
-    return fd_ != -1;
-  }
-
   // Reads |fetch_size| bytes data starting from |start_block|. Puts the result in |buffer|.
   virtual bool ReadBlockAlignedData(uint8_t* buffer, uint32_t fetch_size,
                                     uint32_t start_block) const = 0;
 
-  virtual void Close() = 0;
+  virtual void Close() {}
 
  protected:
   FuseDataProvider() = default;
 
-  // The underlying source to read data from.
-  android::base::unique_fd fd_;
   // Size in bytes of the file to read.
   uint64_t file_size_ = 0;
   // Block size passed to the fuse, this is different from the block size of the block device.
@@ -61,13 +55,18 @@ class FuseDataProvider {
 // This class reads data from a file.
 class FuseFileDataProvider : public FuseDataProvider {
  public:
-  FuseFileDataProvider(android::base::unique_fd&& fd, uint64_t file_size, uint32_t block_size)
-      : FuseDataProvider(std::move(fd), file_size, block_size) {}
-
   FuseFileDataProvider(const std::string& path, uint32_t block_size);
 
   bool ReadBlockAlignedData(uint8_t* buffer, uint32_t fetch_size,
                             uint32_t start_block) const override;
 
+  bool Valid() const {
+    return fd_ != -1;
+  }
+
   void Close() override;
+
+ private:
+  // The underlying source to read data from.
+  android::base::unique_fd fd_;
 };

minadbd/fuse_adb_provider.h

@@ -14,25 +14,24 @@
  * limitations under the License.
  */
 
-#ifndef __FUSE_ADB_PROVIDER_H
-#define __FUSE_ADB_PROVIDER_H
+#pragma once
 
 #include <stdint.h>
 
-#include "android-base/unique_fd.h"
-
 #include "fuse_provider.h"
 
 // This class reads data from adb server.
 class FuseAdbDataProvider : public FuseDataProvider {
  public:
-  FuseAdbDataProvider(android::base::unique_fd&& fd, uint64_t file_size, uint32_t block_size)
-      : FuseDataProvider(std::move(fd), file_size, block_size) {}
+  FuseAdbDataProvider(int fd, uint64_t file_size, uint32_t block_size)
+      : FuseDataProvider(file_size, block_size), fd_(fd) {}
 
   bool ReadBlockAlignedData(uint8_t* buffer, uint32_t fetch_size,
                             uint32_t start_block) const override;
 
   void Close() override;
-};
 
-#endif
+ private:
+  // The underlying source to read data from (i.e. the one that talks to the host).
+  int fd_;
+};

minadbd/minadbd_services.cpp

@@ -96,8 +96,7 @@ static void sideload_host_service(unique_fd sfd, const std::string& args) {
     exit(kMinadbdSocketIOError);
   }
 
-  auto adb_data_reader =
-      std::make_unique<FuseAdbDataProvider>(std::move(sfd), file_size, block_size);
+  auto adb_data_reader = std::make_unique<FuseAdbDataProvider>(sfd, file_size, block_size);
   if (int result = run_fuse_sideload(std::move(adb_data_reader)); result != 0) {
     LOG(ERROR) << "Failed to start fuse";
     exit(kMinadbdFuseStartError);

tests/component/sideload_test.cpp

@@ -22,7 +22,6 @@
 
 #include <android-base/file.h>
 #include <android-base/strings.h>
-#include <android-base/unique_fd.h>
 #include <gtest/gtest.h>
 
 #include "fuse_provider.h"
@@ -32,17 +31,26 @@ TEST(SideloadTest, fuse_device) {
   ASSERT_EQ(0, access("/dev/fuse", R_OK | W_OK));
 }
 
+class FuseTestDataProvider : public FuseDataProvider {
+ public:
+  FuseTestDataProvider(uint64_t file_size, uint32_t block_size)
+      : FuseDataProvider(file_size, block_size) {}
+
+ private:
+  bool ReadBlockAlignedData(uint8_t*, uint32_t, uint32_t) const override {
+    return true;
+  }
+};
+
 TEST(SideloadTest, run_fuse_sideload_wrong_parameters) {
-  auto provider_small_block =
-      std::make_unique<FuseFileDataProvider>(android::base::unique_fd(), 4096, 4095);
+  auto provider_small_block = std::make_unique<FuseTestDataProvider>(4096, 4095);
   ASSERT_EQ(-1, run_fuse_sideload(std::move(provider_small_block)));
 
-  auto provider_large_block =
-      std::make_unique<FuseFileDataProvider>(android::base::unique_fd(), 4096, (1 << 22) + 1);
+  auto provider_large_block = std::make_unique<FuseTestDataProvider>(4096, (1 << 22) + 1);
   ASSERT_EQ(-1, run_fuse_sideload(std::move(provider_large_block)));
 
-  auto provider_too_many_blocks = std::make_unique<FuseFileDataProvider>(
-      android::base::unique_fd(), ((1 << 18) + 1) * 4096, 4096);
+  auto provider_too_many_blocks =
+      std::make_unique<FuseTestDataProvider>(((1 << 18) + 1) * 4096, 4096);
   ASSERT_EQ(-1, run_fuse_sideload(std::move(provider_too_many_blocks)));
 }