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Hook up the backup data writer, and add a utility to read the backup data files.

This commit is contained in:
Joe Onorato 2009-05-19 13:41:21 -07:00 committed by Alex Ray
parent 7ac7ecb6bd
commit 062a488f1e
3 changed files with 164 additions and 63 deletions
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24
include/utils/backup_helpers.h
View File

@ -22,24 +22,27 @@
namespace android {
int back_up_files(int oldSnapshotFD, int oldDataStream, int newSnapshotFD,
char const* fileBase, char const* const* files, int fileCount);
enum {
BACKUP_HEADER_APP_V1 = 0x31707041, // App1 (little endian)
BACKUP_HEADER_ENTITY_V1 = 0x61746144, // Data (little endian)
BACKUP_FOOTER_APP_V1 = 0x746f6f46, // Foot (little endian)
};
// the sizes of all of these match.
typedef struct {
int type; // == APP_MAGIC_V1
int type; // == BACKUP_HEADER_APP_V1
int packageLen; // length of the name of the package that follows, not including the null.
int cookie;
} app_header_v1;
typedef struct {
int type; // ENTITY_MAGIC_V1
int type; // BACKUP_HEADER_ENTITY_V1
int keyLen; // length of the key name, not including the null terminator
int dataSize; // size of the data, not including the padding
int dataSize; // size of the data, not including the padding, -1 means delete
} entity_header_v1;
typedef struct {
int type; // FOOTER_MAGIC_V1
int type; // BACKUP_FOOTER_APP_V1
int entityCount; // the number of entities that were written
int cookie;
} app_footer_v1;
@ -89,11 +92,12 @@ public:
~BackupDataReader();
status_t Status();
status_t ReadNextHeader();
status_t ReadNextHeader(int* type = NULL);
status_t ReadAppHeader(String8* packageName, int* cookie);
bool HasEntities();
status_t ReadEntityHeader(String8* key, size_t* dataSize);
status_t SkipEntityData(); // must be called with the pointer at the begining of the data.
status_t ReadEntityData(void* data, size_t size);
status_t ReadAppFooter(int* cookie);
@ -113,7 +117,11 @@ private:
} m_header;
};
#define TEST_BACKUP_HELPERS 0
int back_up_files(int oldSnapshotFD, BackupDataWriter* dataStream, int newSnapshotFD,
char const* fileBase, char const* const* files, int fileCount);
#define TEST_BACKUP_HELPERS 1
#if TEST_BACKUP_HELPERS
int backup_helper_test_empty();

53
libs/utils/backup_data.cpp
View File

@ -39,10 +39,6 @@ namespace android {
* - 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)
const static int ROUND_UP[4] = { 0, 3, 2, 1 };
static inline size_t
@ -108,7 +104,7 @@ BackupDataWriter::WriteAppHeader(const String8& packageName, int cookie)
nameLen = packageName.length();
header.type = tolel(APP_MAGIC_V1);
header.type = tolel(BACKUP_HEADER_APP_V1);
header.packageLen = tolel(nameLen);
header.cookie = cookie;
@ -148,7 +144,7 @@ BackupDataWriter::WriteEntityHeader(const String8& key, size_t dataSize)
keyLen = key.length();
header.type = tolel(ENTITY_MAGIC_V1);
header.type = tolel(BACKUP_HEADER_ENTITY_V1);
header.keyLen = tolel(keyLen);
header.dataSize = tolel(dataSize);
@ -209,7 +205,7 @@ BackupDataWriter::WriteAppFooter(int cookie)
app_footer_v1 footer;
ssize_t nameLen;
footer.type = tolel(FOOTER_MAGIC_V1);
footer.type = tolel(BACKUP_FOOTER_APP_V1);
footer.entityCount = tolel(m_entityCount);
footer.cookie = cookie;
@ -264,7 +260,7 @@ BackupDataReader::Status()
} while(0)
status_t
BackupDataReader::ReadNextHeader()
BackupDataReader::ReadNextHeader(int* type)
{
if (m_status != NO_ERROR) {
return m_status;
@ -280,7 +276,7 @@ BackupDataReader::ReadNextHeader()
m_header.type = fromlel(m_header.type);
switch (m_header.type)
{
case APP_MAGIC_V1:
case BACKUP_HEADER_APP_V1:
m_header.app.packageLen = fromlel(m_header.app.packageLen);
if (m_header.app.packageLen < 0) {
LOGD("App header at %d has packageLen<0: 0x%08x\n", (int)m_pos,
@ -289,7 +285,7 @@ BackupDataReader::ReadNextHeader()
}
m_header.app.cookie = m_header.app.cookie;
break;
case ENTITY_MAGIC_V1:
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,
@ -297,14 +293,9 @@ BackupDataReader::ReadNextHeader()
m_status = EINVAL;
}
m_header.entity.dataSize = fromlel(m_header.entity.dataSize);
if (m_header.entity.dataSize < 0) {
LOGD("Entity header at %d has dataSize<0: 0x%08x\n", (int)m_pos,
(int)m_header.entity.dataSize);
m_status = EINVAL;
}
m_entityCount++;
break;
case FOOTER_MAGIC_V1:
case BACKUP_FOOTER_APP_V1:
m_header.footer.entityCount = fromlel(m_header.footer.entityCount);
if (m_header.footer.entityCount < 0) {
LOGD("Entity header at %d has entityCount<0: 0x%08x\n", (int)m_pos,
@ -318,6 +309,9 @@ BackupDataReader::ReadNextHeader()
m_status = EINVAL;
}
m_pos += sizeof(m_header);
if (type) {
*type = m_header.type;
}
return m_status;
}
@ -328,7 +322,7 @@ BackupDataReader::ReadAppHeader(String8* packageName, int* cookie)
if (m_status != NO_ERROR) {
return m_status;
}
if (m_header.type != APP_MAGIC_V1) {
if (m_header.type != BACKUP_HEADER_APP_V1) {
return EINVAL;
}
size_t size = m_header.app.packageLen;
@ -349,7 +343,7 @@ BackupDataReader::ReadAppHeader(String8* packageName, int* cookie)
bool
BackupDataReader::HasEntities()
{
return m_status == NO_ERROR && m_header.type == ENTITY_MAGIC_V1;
return m_status == NO_ERROR && m_header.type == BACKUP_HEADER_ENTITY_V1;
}
status_t
@ -358,10 +352,10 @@ BackupDataReader::ReadEntityHeader(String8* key, size_t* dataSize)
if (m_status != NO_ERROR) {
return m_status;
}
if (m_header.type != ENTITY_MAGIC_V1) {
if (m_header.type != BACKUP_HEADER_ENTITY_V1) {
return EINVAL;
}
size_t size = m_header.app.packageLen;
size_t size = m_header.entity.keyLen;
char* buf = key->lockBuffer(size);
if (key == NULL) {
key->unlockBuffer();
@ -377,6 +371,23 @@ BackupDataReader::ReadEntityHeader(String8* key, size_t* 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_header.entity.dataSize, SEEK_CUR);
return pos == -1 ? (int)errno : (int)NO_ERROR;
} else {
return NO_ERROR;
}
}
status_t
BackupDataReader::ReadEntityData(void* data, size_t size)
{
@ -395,7 +406,7 @@ BackupDataReader::ReadAppFooter(int* cookie)
if (m_status != NO_ERROR) {
return m_status;
}
if (m_header.type != FOOTER_MAGIC_V1) {
if (m_header.type != BACKUP_FOOTER_APP_V1) {
return EINVAL;
}
if (m_header.footer.entityCount != m_entityCount) {

150
libs/utils/backup_helper_file.cpp
View File

@ -40,7 +40,7 @@ namespace android {
#define MAGIC0 0x70616e53 // Snap
#define MAGIC1 0x656c6946 // File
#if TEST_BACKUP_HELPERS
#if 0 // TEST_BACKUP_HELPERS
#define LOGP(x...) printf(x)
#else
#define LOGP(x...) LOGD(x)
@ -181,45 +181,105 @@ write_snapshot_file(int fd, const KeyedVector<String8,FileState>& snapshot)
}
static int
write_delete_file(const String8& key)
write_delete_file(BackupDataWriter* dataStream, const String8& key)
{
LOGP("write_delete_file %s\n", key.string());
return 0;
return dataStream->WriteEntityHeader(key, -1);
}
static int
write_update_file(const String8& realFilename, const String8& key)
write_update_file(BackupDataWriter* dataStream, int fd, const String8& key,
const String8& realFilename)
{
LOGP("write_update_file %s (%s)\n", realFilename.string(), key.string());
return 0;
const int bufsize = 4*1024;
int err;
int amt;
int fileSize;
int bytesLeft;
char* buf = (char*)malloc(bufsize);
int crc = crc32(0L, Z_NULL, 0);
bytesLeft = fileSize = lseek(fd, 0, SEEK_END);
lseek(fd, 0, SEEK_SET);
err = dataStream->WriteEntityHeader(key, bytesLeft);
if (err != 0) {
return err;
}
while ((amt = read(fd, buf, bufsize)) != 0 && bytesLeft > 0) {
bytesLeft -= amt;
if (bytesLeft < 0) {
amt += bytesLeft; // Plus a negative is minus. Don't write more than we promised.
}
err = dataStream->WriteEntityData(buf, amt);
if (err != 0) {
return err;
}
}
if (bytesLeft != 0) {
if (bytesLeft > 0) {
// Pad out the space we promised in the buffer. We can't corrupt the buffer,
// even though the data we're sending is probably bad.
memset(buf, 0, bufsize);
while (bytesLeft > 0) {
amt = bytesLeft < bufsize ? bytesLeft : bufsize;
bytesLeft -= amt;
err = dataStream->WriteEntityData(buf, amt);
if (err != 0) {
return err;
}
}
}
LOGE("write_update_file size mismatch for %s. expected=%d actual=%d."
" You aren't doing proper locking!",
realFilename.string(), fileSize, fileSize-bytesLeft);
}
free(buf);
return NO_ERROR;
}
static int
compute_crc32(const String8& filename)
write_update_file(BackupDataWriter* dataStream, const String8& key, const String8& realFilename)
{
int err;
int fd = open(realFilename.string(), O_RDONLY);
if (fd == -1) {
return errno;
}
err = write_update_file(dataStream, fd, key, realFilename);
close(fd);
return err;
}
static int
compute_crc32(int fd)
{
const int bufsize = 4*1024;
int amt;
int fd = open(filename.string(), O_RDONLY);
if (fd == -1) {
return -1;
}
char* buf = (char*)malloc(bufsize);
int crc = crc32(0L, Z_NULL, 0);
lseek(fd, 0, SEEK_SET);
while ((amt = read(fd, buf, bufsize)) != 0) {
crc = crc32(crc, (Bytef*)buf, amt);
}
close(fd);
free(buf);
return crc;
}
int
back_up_files(int oldSnapshotFD, int oldDataStream, int newSnapshotFD,
back_up_files(int oldSnapshotFD, BackupDataWriter* dataStream, int newSnapshotFD,
char const* fileBase, char const* const* files, int fileCount)
{
int err;
@ -252,7 +312,8 @@ back_up_files(int oldSnapshotFD, int oldDataStream, int newSnapshotFD,
s.modTime_nsec = 0; // workaround sim breakage
//s.modTime_nsec = st.st_mtime_nsec;
s.size = st.st_size;
s.crc32 = compute_crc32(realFilename);
// we compute the crc32 later down below, when we already have the file open.
newSnapshot.add(name, s);
}
@ -270,30 +331,42 @@ back_up_files(int oldSnapshotFD, int oldDataStream, int newSnapshotFD,
String8 realFilename(base);
realFilename.appendPath(q);
LOGP("file added: %s\n", realFilename.string());
write_update_file(realFilename, q);
write_update_file(dataStream, q, realFilename);
m++;
}
else if (cmp < 0) {
// file removed
LOGP("file removed: %s\n", p.string());
write_delete_file(p);
dataStream->WriteEntityHeader(p, -1);
n++;
}
else {
// both files exist, check them
String8 realFilename(base);
realFilename.appendPath(q);
const FileState& f = oldSnapshot.valueAt(n);
const FileState& g = newSnapshot.valueAt(m);
FileState& g = newSnapshot.editValueAt(m);
LOGP("%s\n", q.string());
LOGP(" new: modTime=%d,%d size=%-3d crc32=0x%08x\n",
f.modTime_sec, f.modTime_nsec, f.size, f.crc32);
LOGP(" old: modTime=%d,%d size=%-3d crc32=0x%08x\n",
g.modTime_sec, g.modTime_nsec, g.size, g.crc32);
if (f.modTime_sec != g.modTime_sec || f.modTime_nsec != g.modTime_nsec
|| f.size != g.size || f.crc32 != g.crc32) {
write_update_file(realFilename, p);
int fd = open(realFilename.string(), O_RDONLY);
if (fd != -1) {
// We can't open the file. Don't report it as a delete either. Let the
// server keep the old version. Maybe they'll be able to deal with it
// on restore.
} else {
g.crc32 = compute_crc32(fd);
LOGP("%s\n", q.string());
LOGP(" new: modTime=%d,%d size=%-3d crc32=0x%08x\n",
f.modTime_sec, f.modTime_nsec, f.size, f.crc32);
LOGP(" old: modTime=%d,%d size=%-3d crc32=0x%08x\n",
g.modTime_sec, g.modTime_nsec, g.size, g.crc32);
if (f.modTime_sec != g.modTime_sec || f.modTime_nsec != g.modTime_nsec
|| f.size != g.size || f.crc32 != g.crc32) {
write_update_file(dataStream, fd, p, realFilename);
}
close(fd);
}
n++;
m++;
@ -302,7 +375,7 @@ back_up_files(int oldSnapshotFD, int oldDataStream, int newSnapshotFD,
// these were deleted
while (n<N) {
write_delete_file(oldSnapshot.keyAt(n));
dataStream->WriteEntityHeader(oldSnapshot.keyAt(n), -1);
n++;
}
@ -311,7 +384,7 @@ back_up_files(int oldSnapshotFD, int oldDataStream, int newSnapshotFD,
const String8& q = newSnapshot.keyAt(m);
String8 realFilename(base);
realFilename.appendPath(q);
write_update_file(realFilename, q);
write_update_file(dataStream, q, realFilename);
m++;
}
@ -911,10 +984,14 @@ backup_helper_test_files()
fprintf(stderr, "error creating: %s\n", strerror(errno));
return errno;
}
{
BackupDataWriter dataStream(dataStreamFD);
err = back_up_files(-1, dataStreamFD, newSnapshotFD, SCRATCH_DIR, files_before, 5);
if (err != 0) {
return err;
err = back_up_files(-1, &dataStream, newSnapshotFD, SCRATCH_DIR, files_before, 5);
if (err != 0) {
return err;
}
}
close(dataStreamFD);
@ -968,10 +1045,15 @@ backup_helper_test_files()
return errno;
}
err = back_up_files(oldSnapshotFD, dataStreamFD, newSnapshotFD, SCRATCH_DIR, files_after, 6);
if (err != 0) {
return err;
}
{
BackupDataWriter dataStream(dataStreamFD);
err = back_up_files(oldSnapshotFD, &dataStream, newSnapshotFD, SCRATCH_DIR,
files_after, 6);
if (err != 0) {
return err;
}
}
close(oldSnapshotFD);
close(dataStreamFD);