Implement the C++ class to write the backed up file data.
diff --git a/include/utils/ByteOrder.h b/include/utils/ByteOrder.h
index 4c06067..baa3a83 100644
--- a/include/utils/ByteOrder.h
+++ b/include/utils/ByteOrder.h
@@ -38,6 +38,16 @@
* intent is to allow us to avoid byte swapping on the device.
*/
+static inline uint32_t android_swap_long(uint32_t v)
+{
+ return (v<<24) | ((v<<8)&0x00FF0000) | ((v>>8)&0x0000FF00) | (v>>24);
+}
+
+static inline uint16_t android_swap_short(uint16_t v)
+{
+ return (v<<8) | (v>>8);
+}
+
#define DEVICE_BYTE_ORDER LITTLE_ENDIAN
#if BYTE_ORDER == DEVICE_BYTE_ORDER
@@ -49,16 +59,6 @@
#else
-static inline uint32_t android_swap_long(uint32_t v)
-{
- return (v<<24) | ((v<<8)&0x00FF0000) | ((v>>8)&0x0000FF00) | (v>>24);
-}
-
-static inline uint16_t android_swap_short(uint16_t v)
-{
- return (v<<8) | (v>>8);
-}
-
#define dtohl(x) (android_swap_long(x))
#define dtohs(x) (android_swap_short(x))
#define htodl(x) (android_swap_long(x))
@@ -66,4 +66,16 @@
#endif
+#if BYTE_ORDER == LITTLE_ENDIAN
+#define fromlel(x) (x)
+#define fromles(x) (x)
+#define tolel(x) (x)
+#define toles(x) (x)
+#else
+#define fromlel(x) (android_swap_long(x))
+#define fromles(x) (android_swap_short(x))
+#define tolel(x) (android_swap_long(x))
+#define toles(x) (android_swap_short(x))
+#endif
+
#endif // _LIBS_UTILS_BYTE_ORDER_H
diff --git a/include/utils/backup_helpers.h b/include/utils/backup_helpers.h
index 137c5f1..73b9989 100644
--- a/include/utils/backup_helpers.h
+++ b/include/utils/backup_helpers.h
@@ -1,15 +1,69 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
#ifndef _UTILS_BACKUP_HELPERS_H
#define _UTILS_BACKUP_HELPERS_H
+#include <utils/Errors.h>
+#include <utils/String8.h>
+
+namespace android {
+
int back_up_files(int oldSnapshotFD, int oldDataStream, int newSnapshotFD,
char const* fileBase, char const* const* files, int fileCount);
+/**
+ * Reads the data.
+ *
+ * If an error occurs, it poisons this object and all write calls will fail
+ * with the error that occurred.
+ */
+class BackupDataWriter
+{
+public:
+ BackupDataWriter(int fd);
+ // does not close fd
+ ~BackupDataWriter();
+
+ status_t WriteAppHeader(const String8& packageName);
+
+ status_t WriteEntityHeader(const String8& key, size_t dataSize);
+ status_t WriteEntityData(const void* data, size_t size);
+
+ status_t WriteAppFooter();
+
+private:
+ explicit BackupDataWriter();
+ status_t write_padding_for(int n);
+
+ int m_fd;
+ status_t m_status;
+ ssize_t m_pos;
+ int m_entityCount;
+};
+
#define TEST_BACKUP_HELPERS 0
#if TEST_BACKUP_HELPERS
int backup_helper_test_empty();
int backup_helper_test_four();
int backup_helper_test_files();
+int backup_helper_test_data_writer();
#endif
+} // namespace android
+
#endif // _UTILS_BACKUP_HELPERS_H
diff --git a/libs/utils/Android.mk b/libs/utils/Android.mk
index f9fb780..5a1a89b 100644
--- a/libs/utils/Android.mk
+++ b/libs/utils/Android.mk
@@ -117,7 +117,8 @@
IPermissionController.cpp \
IServiceManager.cpp \
Unicode.cpp \
- file_backup_helper.cpp
+ backup_data.cpp \
+ backup_helper_file.cpp
ifeq ($(TARGET_SIMULATOR),true)
LOCAL_SRC_FILES += $(hostSources)
diff --git a/libs/utils/backup_data.cpp b/libs/utils/backup_data.cpp
new file mode 100644
index 0000000..c7f1fdb
--- /dev/null
+++ b/libs/utils/backup_data.cpp
@@ -0,0 +1,236 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <utils/backup_helpers.h>
+#include <utils/ByteOrder.h>
+
+#include <stdio.h>
+#include <unistd.h>
+
+namespace android {
+
+/*
+ * File Format (v1):
+ *
+ * All ints are stored little-endian.
+ *
+ * - An app_header_v1 struct.
+ * - The name of the package, utf-8, null terminated, padded to 4-byte boundary.
+ * - A sequence of zero or more key/value paires (entities), each with
+ * - A entity_header_v1 struct
+ * - The key, utf-8, null terminated, padded to 4-byte boundary.
+ * - The value, padded to 4 byte boundary
+ */
+
+#define APP_MAGIC_V1 0x31707041 // App1 (little endian)
+#define ENTITY_MAGIC_V1 0x61746144 // Data (little endian)
+#define FOOTER_MAGIC_V1 0x746f6f46 // Foot (little endian)
+
+typedef struct {
+ int type; // == APP_MAGIC_V1
+ int packageLen; // length of the name of the package that follows, not including the null.
+} app_header_v1;
+
+typedef struct {
+ int type; // ENTITY_MAGIC_V1
+ int keyLen; // length of the key name, not including the null terminator
+ int dataSize; // size of the data, not including the padding
+} entity_header_v1;
+
+typedef struct {
+ int type; // FOOTER_MAGIC_V1
+ int entityCount; // the number of entities that were written
+} app_footer_v1;
+
+const static int ROUND_UP[4] = { 0, 3, 2, 1 };
+
+static inline size_t
+round_up(size_t n)
+{
+ return n + ROUND_UP[n % 4];
+}
+
+static inline size_t
+padding_extra(size_t n)
+{
+ return ROUND_UP[n % 4];
+}
+
+BackupDataWriter::BackupDataWriter(int fd)
+ :m_fd(fd),
+ m_status(NO_ERROR),
+ m_pos(0),
+ m_entityCount(0)
+{
+}
+
+BackupDataWriter::~BackupDataWriter()
+{
+}
+
+// Pad out anything they've previously written to the next 4 byte boundary.
+status_t
+BackupDataWriter::write_padding_for(int n)
+{
+ ssize_t amt;
+ ssize_t paddingSize;
+
+ paddingSize = padding_extra(n);
+ if (paddingSize > 0) {
+ uint32_t padding = 0xbcbcbcbc;
+ amt = write(m_fd, &padding, paddingSize);
+ if (amt != paddingSize) {
+ m_status = errno;
+ return m_status;
+ }
+ m_pos += amt;
+ }
+ return NO_ERROR;
+}
+
+status_t
+BackupDataWriter::WriteAppHeader(const String8& packageName)
+{
+ if (m_status != NO_ERROR) {
+ return m_status;
+ }
+
+ ssize_t amt;
+
+ amt = write_padding_for(m_pos);
+ if (amt != 0) {
+ return amt;
+ }
+
+ app_header_v1 header;
+ ssize_t nameLen;
+
+ nameLen = packageName.length();
+
+ header.type = tolel(APP_MAGIC_V1);
+ header.packageLen = tolel(nameLen);
+
+ amt = write(m_fd, &header, sizeof(app_header_v1));
+ if (amt != sizeof(app_header_v1)) {
+ m_status = errno;
+ return m_status;
+ }
+ m_pos += amt;
+
+ amt = write(m_fd, packageName.string(), nameLen+1);
+ if (amt != nameLen+1) {
+ m_status = errno;
+ return m_status;
+ }
+ m_pos += amt;
+
+ return NO_ERROR;
+}
+
+status_t
+BackupDataWriter::WriteEntityHeader(const String8& key, size_t dataSize)
+{
+ if (m_status != NO_ERROR) {
+ return m_status;
+ }
+
+ ssize_t amt;
+
+ amt = write_padding_for(m_pos);
+ if (amt != 0) {
+ return amt;
+ }
+
+ entity_header_v1 header;
+ ssize_t keyLen;
+
+ keyLen = key.length();
+
+ header.type = tolel(ENTITY_MAGIC_V1);
+ header.keyLen = tolel(keyLen);
+ header.dataSize = tolel(dataSize);
+
+ amt = write(m_fd, &header, sizeof(entity_header_v1));
+ if (amt != sizeof(entity_header_v1)) {
+ m_status = errno;
+ return m_status;
+ }
+ m_pos += amt;
+
+ amt = write(m_fd, key.string(), keyLen+1);
+ if (amt != keyLen+1) {
+ m_status = errno;
+ return m_status;
+ }
+ m_pos += amt;
+
+ amt = write_padding_for(keyLen+1);
+
+ m_entityCount++;
+
+ return amt;
+}
+
+status_t
+BackupDataWriter::WriteEntityData(const void* data, size_t size)
+{
+ if (m_status != NO_ERROR) {
+ return m_status;
+ }
+
+ // We don't write padding here, because they're allowed to call this several
+ // times with smaller buffers. We write it at the end of WriteEntityHeader
+ // instead.
+ ssize_t amt = write(m_fd, data, size);
+ if (amt != (ssize_t)size) {
+ m_status = errno;
+ return m_status;
+ }
+ m_pos += amt;
+ return NO_ERROR;
+}
+
+status_t
+BackupDataWriter::WriteAppFooter()
+{
+ if (m_status != NO_ERROR) {
+ return m_status;
+ }
+
+ ssize_t amt;
+
+ amt = write_padding_for(m_pos);
+ if (amt != 0) {
+ return amt;
+ }
+
+ app_footer_v1 footer;
+ ssize_t nameLen;
+
+ footer.type = tolel(FOOTER_MAGIC_V1);
+ footer.entityCount = tolel(m_entityCount);
+
+ amt = write(m_fd, &footer, sizeof(app_footer_v1));
+ if (amt != sizeof(app_footer_v1)) {
+ m_status = errno;
+ return m_status;
+ }
+ m_pos += amt;
+
+ return NO_ERROR;
+}
+
+} // namespace android
diff --git a/libs/utils/file_backup_helper.cpp b/libs/utils/backup_helper_file.cpp
similarity index 79%
rename from libs/utils/file_backup_helper.cpp
rename to libs/utils/backup_helper_file.cpp
index 453084a..1fa6a0f 100644
--- a/libs/utils/file_backup_helper.cpp
+++ b/libs/utils/backup_helper_file.cpp
@@ -1,3 +1,19 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
#define LOG_TAG "file_backup_helper"
#include <utils/backup_helpers.h>
@@ -19,13 +35,16 @@
#include <cutils/log.h>
-using namespace android;
+namespace android {
#define MAGIC0 0x70616e53 // Snap
#define MAGIC1 0x656c6946 // File
+#if TEST_BACKUP_HELPERS
+#define LOGP(x...) printf(x)
+#else
#define LOGP(x...) LOGD(x)
-//#define LOGP(x...) printf(x)
+#endif
struct SnapshotHeader {
int magic0;
@@ -118,6 +137,8 @@
bytesWritten += sizeof(FileState) + round_up(name.length());
}
+ LOGP("write_snapshot_file fd=%d\n", fd);
+
int amt;
SnapshotHeader header = { MAGIC0, N, MAGIC1, bytesWritten };
@@ -248,11 +269,13 @@
// file added
String8 realFilename(base);
realFilename.appendPath(q);
+ LOGP("file added: %s\n", realFilename.string());
write_update_file(realFilename, q);
m++;
}
else if (cmp < 0) {
// file removed
+ LOGP("file removed: %s\n", p.string());
write_delete_file(p);
n++;
}
@@ -573,6 +596,107 @@
return matched ? 0 : 1;
}
+// hexdump -v -e '" " 8/1 " 0x%02x," "\n"' data_writer.data
+const unsigned char DATA_GOLDEN_FILE[] = {
+ 0x41, 0x70, 0x70, 0x31, 0x0b, 0x00, 0x00, 0x00,
+ 0x6e, 0x6f, 0x5f, 0x70, 0x61, 0x64, 0x64, 0x69,
+ 0x6e, 0x67, 0x5f, 0x00, 0x44, 0x61, 0x74, 0x61,
+ 0x0b, 0x00, 0x00, 0x00, 0x0c, 0x00, 0x00, 0x00,
+ 0x6e, 0x6f, 0x5f, 0x70, 0x61, 0x64, 0x64, 0x69,
+ 0x6e, 0x67, 0x5f, 0x00, 0x6e, 0x6f, 0x5f, 0x70,
+ 0x61, 0x64, 0x64, 0x69, 0x6e, 0x67, 0x5f, 0x00,
+ 0x41, 0x70, 0x70, 0x31, 0x0c, 0x00, 0x00, 0x00,
+ 0x70, 0x61, 0x64, 0x64, 0x65, 0x64, 0x5f, 0x74,
+ 0x6f, 0x5f, 0x5f, 0x33, 0x00, 0xbc, 0xbc, 0xbc,
+ 0x44, 0x61, 0x74, 0x61, 0x0c, 0x00, 0x00, 0x00,
+ 0x0d, 0x00, 0x00, 0x00, 0x70, 0x61, 0x64, 0x64,
+ 0x65, 0x64, 0x5f, 0x74, 0x6f, 0x5f, 0x5f, 0x33,
+ 0x00, 0xbc, 0xbc, 0xbc, 0x70, 0x61, 0x64, 0x64,
+ 0x65, 0x64, 0x5f, 0x74, 0x6f, 0x5f, 0x5f, 0x33,
+ 0x00, 0xbc, 0xbc, 0xbc, 0x41, 0x70, 0x70, 0x31,
+ 0x0d, 0x00, 0x00, 0x00, 0x70, 0x61, 0x64, 0x64,
+ 0x65, 0x64, 0x5f, 0x74, 0x6f, 0x5f, 0x32, 0x5f,
+ 0x5f, 0x00, 0xbc, 0xbc, 0x44, 0x61, 0x74, 0x61,
+ 0x0d, 0x00, 0x00, 0x00, 0x0e, 0x00, 0x00, 0x00,
+ 0x70, 0x61, 0x64, 0x64, 0x65, 0x64, 0x5f, 0x74,
+ 0x6f, 0x5f, 0x32, 0x5f, 0x5f, 0x00, 0xbc, 0xbc,
+ 0x70, 0x61, 0x64, 0x64, 0x65, 0x64, 0x5f, 0x74,
+ 0x6f, 0x5f, 0x32, 0x5f, 0x5f, 0x00, 0xbc, 0xbc,
+ 0x41, 0x70, 0x70, 0x31, 0x0a, 0x00, 0x00, 0x00,
+ 0x70, 0x61, 0x64, 0x64, 0x65, 0x64, 0x5f, 0x74,
+ 0x6f, 0x31, 0x00, 0xbc, 0x44, 0x61, 0x74, 0x61,
+ 0x0a, 0x00, 0x00, 0x00, 0x0b, 0x00, 0x00, 0x00,
+ 0x70, 0x61, 0x64, 0x64, 0x65, 0x64, 0x5f, 0x74,
+ 0x6f, 0x31, 0x00, 0xbc, 0x70, 0x61, 0x64, 0x64,
+ 0x65, 0x64, 0x5f, 0x74, 0x6f, 0x31, 0x00, 0xbc,
+ 0x46, 0x6f, 0x6f, 0x74, 0x04, 0x00, 0x00, 0x00,
+};
+const int DATA_GOLDEN_FILE_SIZE = sizeof(DATA_GOLDEN_FILE);
+
+static int
+test_write_header_and_entity(BackupDataWriter& writer, const char* str)
+{
+ int err;
+ String8 text(str);
+
+ err = writer.WriteAppHeader(text);
+ if (err != 0) {
+ fprintf(stderr, "WriteAppHeader failed with %s\n", strerror(err));
+ return err;
+ }
+
+ err = writer.WriteEntityHeader(text, text.length()+1);
+ if (err != 0) {
+ fprintf(stderr, "WriteEntityHeader failed with %s\n", strerror(err));
+ return err;
+ }
+
+ err = writer.WriteEntityData(text.string(), text.length()+1);
+ if (err != 0) {
+ fprintf(stderr, "write failed for data '%s'\n", text.string());
+ return errno;
+ }
+
+ return err;
+}
+
+int
+backup_helper_test_data_writer()
+{
+ int err;
+ int fd;
+ const char* filename = SCRATCH_DIR "data_writer.data";
+
+ system("rm -r " SCRATCH_DIR);
+ mkdir(SCRATCH_DIR, 0777);
+ mkdir(SCRATCH_DIR "data", 0777);
+
+ fd = creat(filename, 0666);
+ if (fd == -1) {
+ fprintf(stderr, "error creating: %s\n", strerror(errno));
+ return errno;
+ }
+
+ BackupDataWriter writer(fd);
+
+ err = 0;
+ err |= test_write_header_and_entity(writer, "no_padding_");
+ err |= test_write_header_and_entity(writer, "padded_to__3");
+ err |= test_write_header_and_entity(writer, "padded_to_2__");
+ err |= test_write_header_and_entity(writer, "padded_to1");
+
+ writer.WriteAppFooter();
+
+ close(fd);
+
+ err = compare_file(filename, DATA_GOLDEN_FILE, DATA_GOLDEN_FILE_SIZE);
+ if (err != 0) {
+ return err;
+ }
+
+ return err;
+}
+
static int
get_mod_time(const char* filename, struct timeval times[2])
{
@@ -594,8 +718,9 @@
backup_helper_test_files()
{
int err;
- int newSnapshotFD;
int oldSnapshotFD;
+ int dataStreamFD;
+ int newSnapshotFD;
system("rm -r " SCRATCH_DIR);
mkdir(SCRATCH_DIR, 0777);
@@ -616,17 +741,24 @@
"data/f"
};
+ dataStreamFD = creat(SCRATCH_DIR "1.data", 0666);
+ if (dataStreamFD == -1) {
+ fprintf(stderr, "error creating: %s\n", strerror(errno));
+ return errno;
+ }
+
newSnapshotFD = creat(SCRATCH_DIR "before.snap", 0666);
if (newSnapshotFD == -1) {
fprintf(stderr, "error creating: %s\n", strerror(errno));
return errno;
}
-
- err = back_up_files(-1, newSnapshotFD, 0, SCRATCH_DIR, files_before, 5);
+
+ err = back_up_files(-1, dataStreamFD, newSnapshotFD, SCRATCH_DIR, files_before, 5);
if (err != 0) {
return err;
}
+ close(dataStreamFD);
close(newSnapshotFD);
sleep(3);
@@ -665,21 +797,30 @@
return errno;
}
+ dataStreamFD = creat(SCRATCH_DIR "2.data", 0666);
+ if (dataStreamFD == -1) {
+ fprintf(stderr, "error creating: %s\n", strerror(errno));
+ return errno;
+ }
+
newSnapshotFD = creat(SCRATCH_DIR "after.snap", 0666);
if (newSnapshotFD == -1) {
fprintf(stderr, "error creating: %s\n", strerror(errno));
return errno;
}
- err = back_up_files(oldSnapshotFD, newSnapshotFD, 0, SCRATCH_DIR, files_after, 6);
+ err = back_up_files(oldSnapshotFD, dataStreamFD, newSnapshotFD, SCRATCH_DIR, files_after, 6);
if (err != 0) {
return err;
}
close(oldSnapshotFD);
+ close(dataStreamFD);
close(newSnapshotFD);
return 0;
}
#endif // TEST_BACKUP_HELPERS
+
+}
diff --git a/tests/backup/backup_helper_test.cpp b/tests/backup/backup_helper_test.cpp
index 6da16b4..66240e3 100644
--- a/tests/backup/backup_helper_test.cpp
+++ b/tests/backup/backup_helper_test.cpp
@@ -3,6 +3,8 @@
#include <stdio.h>
#include <string.h>
+using namespace android;
+
#if TEST_BACKUP_HELPERS
// ============================================================
@@ -20,6 +22,7 @@
{ "backup_helper_test_empty", backup_helper_test_empty, 0, false },
{ "backup_helper_test_four", backup_helper_test_four, 0, false },
{ "backup_helper_test_files", backup_helper_test_files, 0, false },
+ { "backup_helper_test_data_writer", backup_helper_test_data_writer, 0, false },
{ 0, NULL, 0, false}
};