unplugged-system/external/icing/icing/store/document-log-creator.cc

206 lines
7.7 KiB
C++

// Copyright (C) 2021 Google LLC
//
// 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 "icing/store/document-log-creator.h"
#include <memory>
#include <string>
#include <utility>
#include "icing/text_classifier/lib3/utils/base/status.h"
#include "icing/text_classifier/lib3/utils/base/statusor.h"
#include "icing/absl_ports/annotate.h"
#include "icing/absl_ports/canonical_errors.h"
#include "icing/absl_ports/str_cat.h"
#include "icing/file/file-backed-proto-log.h"
#include "icing/file/filesystem.h"
#include "icing/file/portable-file-backed-proto-log.h"
#include "icing/proto/document.pb.h"
#include "icing/proto/document_wrapper.pb.h"
#include "icing/util/logging.h"
#include "icing/util/status-macros.h"
namespace icing {
namespace lib {
namespace {
// Used in DocumentId mapper to mark a document as deleted
constexpr char kDocumentLogFilename[] = "document_log";
std::string DocumentLogFilenameV0() {
// Originally only had this one version, no suffix.
return kDocumentLogFilename;
}
std::string DocumentLogFilenameV1() {
return absl_ports::StrCat(kDocumentLogFilename, "_v1");
}
std::string MakeDocumentLogFilenameV0(const std::string& base_dir) {
return absl_ports::StrCat(base_dir, "/", DocumentLogFilenameV0());
}
std::string MakeDocumentLogFilenameV1(const std::string& base_dir) {
return absl_ports::StrCat(base_dir, "/", DocumentLogFilenameV1());
}
} // namespace
std::string DocumentLogCreator::GetDocumentLogFilename() {
// This should always return the latest version of the document log in use.
// The current latest version is V1.
return DocumentLogFilenameV1();
}
libtextclassifier3::StatusOr<DocumentLogCreator::CreateResult>
DocumentLogCreator::Create(const Filesystem* filesystem,
const std::string& base_dir,
int32_t compression_level) {
bool v0_exists =
filesystem->FileExists(MakeDocumentLogFilenameV0(base_dir).c_str());
bool v1_exists =
filesystem->FileExists(MakeDocumentLogFilenameV1(base_dir).c_str());
bool new_file = false;
int preexisting_file_version = kCurrentVersion;
if (v0_exists && !v1_exists) {
ICING_RETURN_IF_ERROR(
MigrateFromV0ToV1(filesystem, base_dir, compression_level));
// Need to regenerate derived files since documents may be written to a
// different file offset in the log.
preexisting_file_version = 0;
} else if (!v1_exists) {
// First time initializing a v1 log. There are no existing derived files at
// this point, so we should generate some. "regenerate" here also means
// "generate for the first time", i.e. we shouldn't expect there to be any
// existing derived files.
new_file = true;
}
ICING_ASSIGN_OR_RETURN(
PortableFileBackedProtoLog<DocumentWrapper>::CreateResult
log_create_result,
PortableFileBackedProtoLog<DocumentWrapper>::Create(
filesystem, MakeDocumentLogFilenameV1(base_dir),
PortableFileBackedProtoLog<DocumentWrapper>::Options(
/*compress_in=*/true,
PortableFileBackedProtoLog<DocumentWrapper>::kMaxProtoSize,
compression_level)));
CreateResult create_result = {std::move(log_create_result),
preexisting_file_version, new_file};
return create_result;
}
libtextclassifier3::Status DocumentLogCreator::MigrateFromV0ToV1(
const Filesystem* filesystem, const std::string& base_dir,
int32_t compression_level) {
ICING_VLOG(1) << "Migrating from v0 to v1 document log.";
// Our v0 proto log was non-portable, create it so we can read protos out from
// it.
auto v0_create_result_or = FileBackedProtoLog<DocumentWrapper>::Create(
filesystem, MakeDocumentLogFilenameV0(base_dir),
FileBackedProtoLog<DocumentWrapper>::Options(/*compress_in=*/true));
if (!v0_create_result_or.ok()) {
return absl_ports::Annotate(
v0_create_result_or.status(),
"Failed to initialize v0 document log while migrating.");
return v0_create_result_or.status();
}
FileBackedProtoLog<DocumentWrapper>::CreateResult v0_create_result =
std::move(v0_create_result_or).ValueOrDie();
std::unique_ptr<FileBackedProtoLog<DocumentWrapper>> v0_proto_log =
std::move(v0_create_result.proto_log);
// Create a v1 portable proto log that we will write our protos to.
auto v1_create_result_or =
PortableFileBackedProtoLog<DocumentWrapper>::Create(
filesystem, MakeDocumentLogFilenameV1(base_dir),
PortableFileBackedProtoLog<DocumentWrapper>::Options(
/*compress_in=*/true,
/*max_proto_size_in=*/
PortableFileBackedProtoLog<DocumentWrapper>::kMaxProtoSize,
/*compression_level_in=*/compression_level));
if (!v1_create_result_or.ok()) {
return absl_ports::Annotate(
v1_create_result_or.status(),
"Failed to initialize v1 document log while migrating.");
}
PortableFileBackedProtoLog<DocumentWrapper>::CreateResult v1_create_result =
std::move(v1_create_result_or).ValueOrDie();
std::unique_ptr<PortableFileBackedProtoLog<DocumentWrapper>> v1_proto_log =
std::move(v1_create_result.proto_log);
// Dummy empty document to be used when copying over deleted documents.
DocumentProto empty_document;
// Start reading out from the old log and putting them in the new log.
ICING_ASSIGN_OR_RETURN(FileBackedProtoLog<DocumentWrapper>::Iterator iterator,
v0_proto_log->GetIterator());
auto iterator_status = iterator.Advance();
while (iterator_status.ok()) {
libtextclassifier3::StatusOr<DocumentWrapper> document_wrapper_or =
v0_proto_log->ReadProto(iterator.GetOffset());
bool deleted_document = false;
DocumentWrapper document_wrapper;
if (absl_ports::IsNotFound(document_wrapper_or.status())) {
// Proto was erased, we can skip copying this into our new log.
*document_wrapper.mutable_document() = empty_document;
deleted_document = true;
} else if (!document_wrapper_or.ok()) {
// Some real error, pass up
return document_wrapper_or.status();
} else {
document_wrapper = std::move(document_wrapper_or).ValueOrDie();
}
auto offset_or = v1_proto_log->WriteProto(document_wrapper);
if (!offset_or.ok()) {
return absl_ports::Annotate(
offset_or.status(),
"Failed to write proto to v1 document log while migrating.");
}
// If the original document was deleted, erase the proto we just wrote.
// We do this to maintain the document_ids, i.e. we still want document_id 2
// to point to a deleted document even though we may not have the document
// contents anymore. DocumentStore guarantees that the document_ids don't
// change unless an Optimize is triggered.
if (deleted_document) {
int64_t offset = offset_or.ValueOrDie();
auto erased_status = v1_proto_log->EraseProto(offset);
if (!erased_status.ok()) {
return absl_ports::Annotate(
erased_status,
"Failed to erase proto in v1 document log while migrating.");
}
}
iterator_status = iterator.Advance();
}
// Close out our file log pointers.
v0_proto_log.reset();
v1_proto_log.reset();
return libtextclassifier3::Status::OK;
}
} // namespace lib
} // namespace icing