作者: 韩晨旭 10225101440 李畅 10225102463
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// Copyright (c) 2012 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#include <stdio.h>
#include "db/dbformat.h"
#include "db/filename.h"
#include "db/log_reader.h"
#include "db/version_edit.h"
#include "db/write_batch_internal.h"
#include "leveldb/env.h"
#include "leveldb/iterator.h"
#include "leveldb/options.h"
#include "leveldb/status.h"
#include "leveldb/table.h"
#include "leveldb/write_batch.h"
#include "util/logging.h"
namespace leveldb {
namespace {
bool GuessType(const std::string& fname, FileType* type) {
size_t pos = fname.rfind('/');
std::string basename;
if (pos == std::string::npos) {
basename = fname;
} else {
basename = std::string(fname.data() + pos + 1, fname.size() - pos - 1);
}
uint64_t ignored;
return ParseFileName(basename, &ignored, type);
}
// Notified when log reader encounters corruption.
class CorruptionReporter : public log::Reader::Reporter {
public:
virtual void Corruption(size_t bytes, const Status& status) {
printf("corruption: %d bytes; %s\n",
static_cast<int>(bytes),
status.ToString().c_str());
}
};
// Print contents of a log file. (*func)() is called on every record.
bool PrintLogContents(Env* env, const std::string& fname,
void (*func)(Slice)) {
SequentialFile* file;
Status s = env->NewSequentialFile(fname, &file);
if (!s.ok()) {
fprintf(stderr, "%s\n", s.ToString().c_str());
return false;
}
CorruptionReporter reporter;
log::Reader reader(file, &reporter, true, 0);
Slice record;
std::string scratch;
while (reader.ReadRecord(&record, &scratch)) {
printf("--- offset %llu; ",
static_cast<unsigned long long>(reader.LastRecordOffset()));
(*func)(record);
}
delete file;
return true;
}
// Called on every item found in a WriteBatch.
class WriteBatchItemPrinter : public WriteBatch::Handler {
public:
uint64_t offset_;
uint64_t sequence_;
virtual void Put(const Slice& key, const Slice& value) {
printf(" put '%s' '%s'\n",
EscapeString(key).c_str(),
EscapeString(value).c_str());
}
virtual void Delete(const Slice& key) {
printf(" del '%s'\n",
EscapeString(key).c_str());
}
};
// Called on every log record (each one of which is a WriteBatch)
// found in a kLogFile.
static void WriteBatchPrinter(Slice record) {
if (record.size() < 12) {
printf("log record length %d is too small\n",
static_cast<int>(record.size()));
return;
}
WriteBatch batch;
WriteBatchInternal::SetContents(&batch, record);
printf("sequence %llu\n",
static_cast<unsigned long long>(WriteBatchInternal::Sequence(&batch)));
WriteBatchItemPrinter batch_item_printer;
Status s = batch.Iterate(&batch_item_printer);
if (!s.ok()) {
printf(" error: %s\n", s.ToString().c_str());
}
}
bool DumpLog(Env* env, const std::string& fname) {
return PrintLogContents(env, fname, WriteBatchPrinter);
}
// Called on every log record (each one of which is a WriteBatch)
// found in a kDescriptorFile.
static void VersionEditPrinter(Slice record) {
VersionEdit edit;
Status s = edit.DecodeFrom(record);
if (!s.ok()) {
printf("%s\n", s.ToString().c_str());
return;
}
printf("%s", edit.DebugString().c_str());
}
bool DumpDescriptor(Env* env, const std::string& fname) {
return PrintLogContents(env, fname, VersionEditPrinter);
}
bool DumpTable(Env* env, const std::string& fname) {
uint64_t file_size;
RandomAccessFile* file = NULL;
Table* table = NULL;
Status s = env->GetFileSize(fname, &file_size);
if (s.ok()) {
s = env->NewRandomAccessFile(fname, &file);
}
if (s.ok()) {
// We use the default comparator, which may or may not match the
// comparator used in this database. However this should not cause
// problems since we only use Table operations that do not require
// any comparisons. In particular, we do not call Seek or Prev.
s = Table::Open(Options(), file, file_size, &table);
}
if (!s.ok()) {
fprintf(stderr, "%s\n", s.ToString().c_str());
delete table;
delete file;
return false;
}
ReadOptions ro;
ro.fill_cache = false;
Iterator* iter = table->NewIterator(ro);
for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
ParsedInternalKey key;
if (!ParseInternalKey(iter->key(), &key)) {
printf("badkey '%s' => '%s'\n",
EscapeString(iter->key()).c_str(),
EscapeString(iter->value()).c_str());
} else {
char kbuf[20];
const char* type;
if (key.type == kTypeDeletion) {
type = "del";
} else if (key.type == kTypeValue) {
type = "val";
} else {
snprintf(kbuf, sizeof(kbuf), "%d", static_cast<int>(key.type));
type = kbuf;
}
printf("'%s' @ %8llu : %s => '%s'\n",
EscapeString(key.user_key).c_str(),
static_cast<unsigned long long>(key.sequence),
type,
EscapeString(iter->value()).c_str());
}
}
s = iter->status();
if (!s.ok()) {
printf("iterator error: %s\n", s.ToString().c_str());
}
delete iter;
delete table;
delete file;
return true;
}
bool DumpFile(Env* env, const std::string& fname) {
FileType ftype;
if (!GuessType(fname, &ftype)) {
fprintf(stderr, "%s: unknown file type\n", fname.c_str());
return false;
}
switch (ftype) {
case kLogFile: return DumpLog(env, fname);
case kDescriptorFile: return DumpDescriptor(env, fname);
case kTableFile: return DumpTable(env, fname);
default: {
fprintf(stderr, "%s: not a dump-able file type\n", fname.c_str());
break;
}
}
return false;
}
bool HandleDumpCommand(Env* env, char** files, int num) {
bool ok = true;
for (int i = 0; i < num; i++) {
ok &= DumpFile(env, files[i]);
}
return ok;
}
}
} // namespace leveldb
static void Usage() {
fprintf(
stderr,
"Usage: leveldbutil command...\n"
" dump files... -- dump contents of specified files\n"
);
}
int main(int argc, char** argv) {
leveldb::Env* env = leveldb::Env::Default();
bool ok = true;
if (argc < 2) {
Usage();
ok = false;
} else {
std::string command = argv[1];
if (command == "dump") {
ok = leveldb::HandleDumpCommand(env, argv+2, argc-2);
} else {
Usage();
ok = false;
}
}
return (ok ? 0 : 1);
}