Add Truncate to SmbProviderClient

Adds Truncate to SmbProviderClient and FakeSmbProviderClient

CQ-DEPEND=CL:879387

Bug: chromium:757625
Change-Id: Iff2f62efc059a41ad4d15c3cbb18bafac277c690
Reviewed-on: https://chromium-review.googlesource.com/879566
Commit-Queue: Allen Vicencio <allenvic@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533156}

chromeos/dbus/fake_smb_provider_client.cc

@@ -88,4 +88,12 @@ void FakeSmbProviderClient::CreateFile(int32_t mount_id,
       FROM_HERE, base::BindOnce(std::move(callback), smbprovider::ERROR_OK));
 }
 
+void FakeSmbProviderClient::Truncate(int32_t mount_id,
+                                     const base::FilePath& file_path,
+                                     int64_t length,
+                                     StatusCallback callback) {
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::BindOnce(std::move(callback), smbprovider::ERROR_OK));
+}
+
 }  // namespace chromeos

chromeos/dbus/fake_smb_provider_client.h

@@ -49,6 +49,11 @@ class CHROMEOS_EXPORT FakeSmbProviderClient : public SmbProviderClient {
                   const base::FilePath& file_path,
                   StatusCallback callback) override;
 
+  void Truncate(int32_t mount_id,
+                const base::FilePath& file_path,
+                int64_t length,
+                StatusCallback callback) override;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(FakeSmbProviderClient);
 };

chromeos/dbus/smb_provider_client.cc

@@ -148,6 +148,18 @@ class SmbProviderClientImpl : public SmbProviderClient {
                &SmbProviderClientImpl::HandleCreateFileCallback, &callback);
   }
 
+  void Truncate(int32_t mount_id,
+                const base::FilePath& file_path,
+                int64_t length,
+                StatusCallback callback) override {
+    smbprovider::TruncateOptionsProto options;
+    options.set_mount_id(mount_id);
+    options.set_file_path(file_path.value());
+    options.set_length(length);
+    CallMethod(smbprovider::kTruncateMethod, options,
+               &SmbProviderClientImpl::HandleTruncateCallback, &callback);
+  }
+
  protected:
   // DBusClient override.
   void Init(dbus::Bus* bus) override {
@@ -287,6 +299,17 @@ class SmbProviderClientImpl : public SmbProviderClient {
     std::move(callback).Run(GetErrorFromReader(&reader));
   }
 
+  // Handles D-Bus callback for Truncate.
+  void HandleTruncateCallback(StatusCallback callback,
+                              dbus::Response* response) {
+    if (!response) {
+      DLOG(ERROR) << "Truncate: failed to call smbprovider";
+      std::move(callback).Run(smbprovider::ERROR_DBUS_PARSE_FAILED);
+    }
+    dbus::MessageReader reader(response);
+    std::move(callback).Run(GetErrorFromReader(&reader));
+  }
+
   // Handles D-Bus responses for methods that return an error and a protobuf
   // object.
   template <class T>

chromeos/dbus/smb_provider_client.h

@@ -102,6 +102,13 @@ class CHROMEOS_EXPORT SmbProviderClient : public DBusClient {
                           const base::FilePath& file_path,
                           StatusCallback callback) = 0;
 
+  // Calls Truncate. Using the corresponding mount |mount_id|, this truncates
+  // the file in |file_path| to the desired |length|.
+  virtual void Truncate(int32_t mount_id,
+                        const base::FilePath& file_path,
+                        int64_t length,
+                        StatusCallback callback) = 0;
+
  protected:
   // Create() should be used instead.
   SmbProviderClient();