donut snapshot
diff --git a/libs/utils/BackupData.cpp b/libs/utils/BackupData.cpp
new file mode 100644
index 0000000..cce754a
--- /dev/null
+++ b/libs/utils/BackupData.cpp
@@ -0,0 +1,349 @@
+/*
+ * 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 "backup_data"
+
+#include <utils/BackupHelpers.h>
+#include <utils/ByteOrder.h>
+
+#include <stdio.h>
+#include <unistd.h>
+
+#include <cutils/log.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
+ */
+
+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::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;
+ }
+
+ String8 k;
+ if (m_keyPrefix.length() > 0) {
+ k = m_keyPrefix;
+ k += ":";
+ k += key;
+ } else {
+ k = key;
+ }
+ if (true) {
+ LOGD("Writing entity: prefix='%s' key='%s' dataSize=%d", m_keyPrefix.string(), key.string(),
+ dataSize);
+ }
+
+ entity_header_v1 header;
+ ssize_t keyLen;
+
+ keyLen = k.length();
+
+ header.type = tolel(BACKUP_HEADER_ENTITY_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, k.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;
+}
+
+void
+BackupDataWriter::SetKeyPrefix(const String8& keyPrefix)
+{
+ m_keyPrefix = keyPrefix;
+}
+
+
+BackupDataReader::BackupDataReader(int fd)
+ :m_fd(fd),
+ m_done(false),
+ m_status(NO_ERROR),
+ m_pos(0),
+ m_entityCount(0)
+{
+ memset(&m_header, 0, sizeof(m_header));
+}
+
+BackupDataReader::~BackupDataReader()
+{
+}
+
+status_t
+BackupDataReader::Status()
+{
+ return m_status;
+}
+
+#define CHECK_SIZE(actual, expected) \
+ do { \
+ if ((actual) != (expected)) { \
+ if ((actual) == 0) { \
+ m_status = EIO; \
+ } else { \
+ m_status = errno; \
+ } \
+ return m_status; \
+ } \
+ } while(0)
+#define SKIP_PADDING() \
+ do { \
+ status_t err = skip_padding(); \
+ if (err != NO_ERROR) { \
+ m_status = err; \
+ return err; \
+ } \
+ } while(0)
+
+status_t
+BackupDataReader::ReadNextHeader(bool* done, int* type)
+{
+ *done = m_done;
+ if (m_status != NO_ERROR) {
+ return m_status;
+ }
+
+ int amt;
+
+ // No error checking here, in case we're at the end of the stream. Just let read() fail.
+ skip_padding();
+ amt = read(m_fd, &m_header, sizeof(m_header));
+ *done = m_done = (amt == 0);
+ CHECK_SIZE(amt, sizeof(m_header));
+ m_pos += sizeof(m_header);
+ if (type) {
+ *type = m_header.type;
+ }
+
+ // validate and fix up the fields.
+ m_header.type = fromlel(m_header.type);
+ switch (m_header.type)
+ {
+ case BACKUP_HEADER_ENTITY_V1:
+ {
+ m_header.entity.keyLen = fromlel(m_header.entity.keyLen);
+ if (m_header.entity.keyLen <= 0) {
+ LOGD("Entity header at %d has keyLen<=0: 0x%08x\n", (int)m_pos,
+ (int)m_header.entity.keyLen);
+ m_status = EINVAL;
+ }
+ m_header.entity.dataSize = fromlel(m_header.entity.dataSize);
+ m_entityCount++;
+
+ // read the rest of the header (filename)
+ size_t size = m_header.entity.keyLen;
+ char* buf = m_key.lockBuffer(size);
+ if (buf == NULL) {
+ m_status = ENOMEM;
+ return m_status;
+ }
+ int amt = read(m_fd, buf, size+1);
+ CHECK_SIZE(amt, (int)size+1);
+ m_key.unlockBuffer(size);
+ m_pos += size+1;
+ SKIP_PADDING();
+ m_dataEndPos = m_pos + m_header.entity.dataSize;
+
+ break;
+ }
+ default:
+ LOGD("Chunk header at %d has invalid type: 0x%08x", (int)m_pos, (int)m_header.type);
+ m_status = EINVAL;
+ }
+
+ return m_status;
+}
+
+bool
+BackupDataReader::HasEntities()
+{
+ return m_status == NO_ERROR && m_header.type == BACKUP_HEADER_ENTITY_V1;
+}
+
+status_t
+BackupDataReader::ReadEntityHeader(String8* key, size_t* dataSize)
+{
+ if (m_status != NO_ERROR) {
+ return m_status;
+ }
+ if (m_header.type != BACKUP_HEADER_ENTITY_V1) {
+ return EINVAL;
+ }
+ *key = m_key;
+ *dataSize = m_header.entity.dataSize;
+ return NO_ERROR;
+}
+
+status_t
+BackupDataReader::SkipEntityData()
+{
+ if (m_status != NO_ERROR) {
+ return m_status;
+ }
+ if (m_header.type != BACKUP_HEADER_ENTITY_V1) {
+ return EINVAL;
+ }
+ if (m_header.entity.dataSize > 0) {
+ int pos = lseek(m_fd, m_dataEndPos, SEEK_SET);
+ return pos == -1 ? (int)errno : (int)NO_ERROR;
+ } else {
+ return NO_ERROR;
+ }
+}
+
+ssize_t
+BackupDataReader::ReadEntityData(void* data, size_t size)
+{
+ if (m_status != NO_ERROR) {
+ return -1;
+ }
+ int remaining = m_dataEndPos - m_pos;
+ //LOGD("ReadEntityData size=%d m_pos=0x%x m_dataEndPos=0x%x remaining=%d\n",
+ // size, m_pos, m_dataEndPos, remaining);
+ if (remaining <= 0) {
+ return 0;
+ }
+ if (((int)size) > remaining) {
+ size = remaining;
+ }
+ //LOGD(" reading %d bytes", size);
+ int amt = read(m_fd, data, size);
+ if (amt < 0) {
+ m_status = errno;
+ return -1;
+ }
+ m_pos += amt;
+ return amt;
+}
+
+status_t
+BackupDataReader::skip_padding()
+{
+ ssize_t amt;
+ ssize_t paddingSize;
+
+ paddingSize = padding_extra(m_pos);
+ if (paddingSize > 0) {
+ uint32_t padding;
+ amt = read(m_fd, &padding, paddingSize);
+ CHECK_SIZE(amt, paddingSize);
+ m_pos += amt;
+ }
+ return NO_ERROR;
+}
+
+
+} // namespace android