rocksdb/db/blob/blob_file_reader.h

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Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#pragma once
#include <cinttypes>
#include <memory>
#include "db/blob/blob_read_request.h"
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
#include "file/random_access_file_reader.h"
#include "rocksdb/compression_type.h"
#include "rocksdb/rocksdb_namespace.h"
#include "util/autovector.h"
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
namespace ROCKSDB_NAMESPACE {
class Status;
struct ImmutableOptions;
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
struct FileOptions;
class HistogramImpl;
struct ReadOptions;
class Slice;
class FilePrefetchBuffer;
class BlobContents;
class Statistics;
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
class BlobFileReader {
public:
static Status Create(const ImmutableOptions& immutable_options,
Group rocksdb.sst.read.micros stat by IOActivity flush and compaction (#11288) Summary: **Context:** The existing stat rocksdb.sst.read.micros does not reflect each of compaction and flush cases but aggregate them, which is not so helpful for us to understand IO read behavior of each of them. **Summary** - Update `StopWatch` and `RandomAccessFileReader` to record `rocksdb.sst.read.micros` and `rocksdb.file.{flush/compaction}.read.micros` - Fixed the default histogram in `RandomAccessFileReader` - New field `ReadOptions/IOOptions::io_activity`; Pass `ReadOptions` through paths under db open, flush and compaction to where we can prepare `IOOptions` and pass it to `RandomAccessFileReader` - Use `thread_status_util` for assertion in `DbStressFSWrapper` for continuous testing on we are passing correct `io_activity` under db open, flush and compaction Pull Request resolved: https://github.com/facebook/rocksdb/pull/11288 Test Plan: - **Stress test** - **Db bench 1: rocksdb.sst.read.micros COUNT ≈ sum of rocksdb.file.read.flush.micros's and rocksdb.file.read.compaction.micros's.** (without blob) - May not be exactly the same due to `HistogramStat::Add` only guarantees atomic not accuracy across threads. ``` ./db_bench -db=/dev/shm/testdb/ -statistics=true -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3 (-use_plain_table=1 -prefix_size=10) ``` ``` // BlockBasedTable rocksdb.sst.read.micros P50 : 2.009374 P95 : 4.968548 P99 : 8.110362 P100 : 43.000000 COUNT : 40456 SUM : 114805 rocksdb.file.read.flush.micros P50 : 1.871841 P95 : 3.872407 P99 : 5.540541 P100 : 43.000000 COUNT : 2250 SUM : 6116 rocksdb.file.read.compaction.micros P50 : 2.023109 P95 : 5.029149 P99 : 8.196910 P100 : 26.000000 COUNT : 38206 SUM : 108689 // PlainTable Does not apply ``` - **Db bench 2: performance** **Read** SETUP: db with 900 files ``` ./db_bench -db=/dev/shm/testdb/ -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=true -target_file_size_base=655 -compression_type=none ```run till convergence ``` ./db_bench -seed=1678564177044286 -use_existing_db=true -db=/dev/shm/testdb -benchmarks=readrandom[-X60] -statistics=true -num=1000000 -disable_auto_compactions=true -compression_type=none -bloom_bits=3 ``` Pre-change `readrandom [AVG 60 runs] : 21568 (± 248) ops/sec` Post-change (no regression, -0.3%) `readrandom [AVG 60 runs] : 21486 (± 236) ops/sec` **Compaction/Flush**run till convergence ``` ./db_bench -db=/dev/shm/testdb2/ -seed=1678564177044286 -benchmarks="fillseq[-X60]" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=false -target_file_size_base=655 -compression_type=none rocksdb.sst.read.micros COUNT : 33820 rocksdb.sst.read.flush.micros COUNT : 1800 rocksdb.sst.read.compaction.micros COUNT : 32020 ``` Pre-change `fillseq [AVG 46 runs] : 1391 (± 214) ops/sec; 0.7 (± 0.1) MB/sec` Post-change (no regression, ~-0.4%) `fillseq [AVG 46 runs] : 1385 (± 216) ops/sec; 0.7 (± 0.1) MB/sec` Reviewed By: ajkr Differential Revision: D44007011 Pulled By: hx235 fbshipit-source-id: a54c89e4846dfc9a135389edf3f3eedfea257132
2023-04-21 16:07:18 +00:00
const ReadOptions& read_options,
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
const FileOptions& file_options,
uint32_t column_family_id,
HistogramImpl* blob_file_read_hist,
uint64_t blob_file_number,
const std::shared_ptr<IOTracer>& io_tracer,
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
std::unique_ptr<BlobFileReader>* reader);
BlobFileReader(const BlobFileReader&) = delete;
BlobFileReader& operator=(const BlobFileReader&) = delete;
~BlobFileReader();
Status GetBlob(const ReadOptions& read_options, const Slice& user_key,
uint64_t offset, uint64_t value_size,
CompressionType compression_type,
FilePrefetchBuffer* prefetch_buffer,
MemoryAllocator* allocator,
std::unique_ptr<BlobContents>* result,
uint64_t* bytes_read) const;
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
// offsets must be sorted in ascending order by caller.
void MultiGetBlob(
const ReadOptions& read_options, MemoryAllocator* allocator,
autovector<std::pair<BlobReadRequest*, std::unique_ptr<BlobContents>>>&
blob_reqs,
uint64_t* bytes_read) const;
CompressionType GetCompressionType() const { return compression_type_; }
uint64_t GetFileSize() const { return file_size_; }
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
private:
BlobFileReader(std::unique_ptr<RandomAccessFileReader>&& file_reader,
uint64_t file_size, CompressionType compression_type,
SystemClock* clock, Statistics* statistics);
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
static Status OpenFile(const ImmutableOptions& immutable_options,
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
const FileOptions& file_opts,
HistogramImpl* blob_file_read_hist,
uint64_t blob_file_number,
const std::shared_ptr<IOTracer>& io_tracer,
uint64_t* file_size,
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
std::unique_ptr<RandomAccessFileReader>* file_reader);
static Status ReadHeader(const RandomAccessFileReader* file_reader,
Group rocksdb.sst.read.micros stat by IOActivity flush and compaction (#11288) Summary: **Context:** The existing stat rocksdb.sst.read.micros does not reflect each of compaction and flush cases but aggregate them, which is not so helpful for us to understand IO read behavior of each of them. **Summary** - Update `StopWatch` and `RandomAccessFileReader` to record `rocksdb.sst.read.micros` and `rocksdb.file.{flush/compaction}.read.micros` - Fixed the default histogram in `RandomAccessFileReader` - New field `ReadOptions/IOOptions::io_activity`; Pass `ReadOptions` through paths under db open, flush and compaction to where we can prepare `IOOptions` and pass it to `RandomAccessFileReader` - Use `thread_status_util` for assertion in `DbStressFSWrapper` for continuous testing on we are passing correct `io_activity` under db open, flush and compaction Pull Request resolved: https://github.com/facebook/rocksdb/pull/11288 Test Plan: - **Stress test** - **Db bench 1: rocksdb.sst.read.micros COUNT ≈ sum of rocksdb.file.read.flush.micros's and rocksdb.file.read.compaction.micros's.** (without blob) - May not be exactly the same due to `HistogramStat::Add` only guarantees atomic not accuracy across threads. ``` ./db_bench -db=/dev/shm/testdb/ -statistics=true -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3 (-use_plain_table=1 -prefix_size=10) ``` ``` // BlockBasedTable rocksdb.sst.read.micros P50 : 2.009374 P95 : 4.968548 P99 : 8.110362 P100 : 43.000000 COUNT : 40456 SUM : 114805 rocksdb.file.read.flush.micros P50 : 1.871841 P95 : 3.872407 P99 : 5.540541 P100 : 43.000000 COUNT : 2250 SUM : 6116 rocksdb.file.read.compaction.micros P50 : 2.023109 P95 : 5.029149 P99 : 8.196910 P100 : 26.000000 COUNT : 38206 SUM : 108689 // PlainTable Does not apply ``` - **Db bench 2: performance** **Read** SETUP: db with 900 files ``` ./db_bench -db=/dev/shm/testdb/ -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=true -target_file_size_base=655 -compression_type=none ```run till convergence ``` ./db_bench -seed=1678564177044286 -use_existing_db=true -db=/dev/shm/testdb -benchmarks=readrandom[-X60] -statistics=true -num=1000000 -disable_auto_compactions=true -compression_type=none -bloom_bits=3 ``` Pre-change `readrandom [AVG 60 runs] : 21568 (± 248) ops/sec` Post-change (no regression, -0.3%) `readrandom [AVG 60 runs] : 21486 (± 236) ops/sec` **Compaction/Flush**run till convergence ``` ./db_bench -db=/dev/shm/testdb2/ -seed=1678564177044286 -benchmarks="fillseq[-X60]" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=false -target_file_size_base=655 -compression_type=none rocksdb.sst.read.micros COUNT : 33820 rocksdb.sst.read.flush.micros COUNT : 1800 rocksdb.sst.read.compaction.micros COUNT : 32020 ``` Pre-change `fillseq [AVG 46 runs] : 1391 (± 214) ops/sec; 0.7 (± 0.1) MB/sec` Post-change (no regression, ~-0.4%) `fillseq [AVG 46 runs] : 1385 (± 216) ops/sec; 0.7 (± 0.1) MB/sec` Reviewed By: ajkr Differential Revision: D44007011 Pulled By: hx235 fbshipit-source-id: a54c89e4846dfc9a135389edf3f3eedfea257132
2023-04-21 16:07:18 +00:00
const ReadOptions& read_options,
uint32_t column_family_id, Statistics* statistics,
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
CompressionType* compression_type);
static Status ReadFooter(const RandomAccessFileReader* file_reader,
Group rocksdb.sst.read.micros stat by IOActivity flush and compaction (#11288) Summary: **Context:** The existing stat rocksdb.sst.read.micros does not reflect each of compaction and flush cases but aggregate them, which is not so helpful for us to understand IO read behavior of each of them. **Summary** - Update `StopWatch` and `RandomAccessFileReader` to record `rocksdb.sst.read.micros` and `rocksdb.file.{flush/compaction}.read.micros` - Fixed the default histogram in `RandomAccessFileReader` - New field `ReadOptions/IOOptions::io_activity`; Pass `ReadOptions` through paths under db open, flush and compaction to where we can prepare `IOOptions` and pass it to `RandomAccessFileReader` - Use `thread_status_util` for assertion in `DbStressFSWrapper` for continuous testing on we are passing correct `io_activity` under db open, flush and compaction Pull Request resolved: https://github.com/facebook/rocksdb/pull/11288 Test Plan: - **Stress test** - **Db bench 1: rocksdb.sst.read.micros COUNT ≈ sum of rocksdb.file.read.flush.micros's and rocksdb.file.read.compaction.micros's.** (without blob) - May not be exactly the same due to `HistogramStat::Add` only guarantees atomic not accuracy across threads. ``` ./db_bench -db=/dev/shm/testdb/ -statistics=true -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3 (-use_plain_table=1 -prefix_size=10) ``` ``` // BlockBasedTable rocksdb.sst.read.micros P50 : 2.009374 P95 : 4.968548 P99 : 8.110362 P100 : 43.000000 COUNT : 40456 SUM : 114805 rocksdb.file.read.flush.micros P50 : 1.871841 P95 : 3.872407 P99 : 5.540541 P100 : 43.000000 COUNT : 2250 SUM : 6116 rocksdb.file.read.compaction.micros P50 : 2.023109 P95 : 5.029149 P99 : 8.196910 P100 : 26.000000 COUNT : 38206 SUM : 108689 // PlainTable Does not apply ``` - **Db bench 2: performance** **Read** SETUP: db with 900 files ``` ./db_bench -db=/dev/shm/testdb/ -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=true -target_file_size_base=655 -compression_type=none ```run till convergence ``` ./db_bench -seed=1678564177044286 -use_existing_db=true -db=/dev/shm/testdb -benchmarks=readrandom[-X60] -statistics=true -num=1000000 -disable_auto_compactions=true -compression_type=none -bloom_bits=3 ``` Pre-change `readrandom [AVG 60 runs] : 21568 (± 248) ops/sec` Post-change (no regression, -0.3%) `readrandom [AVG 60 runs] : 21486 (± 236) ops/sec` **Compaction/Flush**run till convergence ``` ./db_bench -db=/dev/shm/testdb2/ -seed=1678564177044286 -benchmarks="fillseq[-X60]" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=false -target_file_size_base=655 -compression_type=none rocksdb.sst.read.micros COUNT : 33820 rocksdb.sst.read.flush.micros COUNT : 1800 rocksdb.sst.read.compaction.micros COUNT : 32020 ``` Pre-change `fillseq [AVG 46 runs] : 1391 (± 214) ops/sec; 0.7 (± 0.1) MB/sec` Post-change (no regression, ~-0.4%) `fillseq [AVG 46 runs] : 1385 (± 216) ops/sec; 0.7 (± 0.1) MB/sec` Reviewed By: ajkr Differential Revision: D44007011 Pulled By: hx235 fbshipit-source-id: a54c89e4846dfc9a135389edf3f3eedfea257132
2023-04-21 16:07:18 +00:00
const ReadOptions& read_options, uint64_t file_size,
Statistics* statistics);
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
using Buffer = std::unique_ptr<char[]>;
static Status ReadFromFile(const RandomAccessFileReader* file_reader,
Group rocksdb.sst.read.micros stat by IOActivity flush and compaction (#11288) Summary: **Context:** The existing stat rocksdb.sst.read.micros does not reflect each of compaction and flush cases but aggregate them, which is not so helpful for us to understand IO read behavior of each of them. **Summary** - Update `StopWatch` and `RandomAccessFileReader` to record `rocksdb.sst.read.micros` and `rocksdb.file.{flush/compaction}.read.micros` - Fixed the default histogram in `RandomAccessFileReader` - New field `ReadOptions/IOOptions::io_activity`; Pass `ReadOptions` through paths under db open, flush and compaction to where we can prepare `IOOptions` and pass it to `RandomAccessFileReader` - Use `thread_status_util` for assertion in `DbStressFSWrapper` for continuous testing on we are passing correct `io_activity` under db open, flush and compaction Pull Request resolved: https://github.com/facebook/rocksdb/pull/11288 Test Plan: - **Stress test** - **Db bench 1: rocksdb.sst.read.micros COUNT ≈ sum of rocksdb.file.read.flush.micros's and rocksdb.file.read.compaction.micros's.** (without blob) - May not be exactly the same due to `HistogramStat::Add` only guarantees atomic not accuracy across threads. ``` ./db_bench -db=/dev/shm/testdb/ -statistics=true -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3 (-use_plain_table=1 -prefix_size=10) ``` ``` // BlockBasedTable rocksdb.sst.read.micros P50 : 2.009374 P95 : 4.968548 P99 : 8.110362 P100 : 43.000000 COUNT : 40456 SUM : 114805 rocksdb.file.read.flush.micros P50 : 1.871841 P95 : 3.872407 P99 : 5.540541 P100 : 43.000000 COUNT : 2250 SUM : 6116 rocksdb.file.read.compaction.micros P50 : 2.023109 P95 : 5.029149 P99 : 8.196910 P100 : 26.000000 COUNT : 38206 SUM : 108689 // PlainTable Does not apply ``` - **Db bench 2: performance** **Read** SETUP: db with 900 files ``` ./db_bench -db=/dev/shm/testdb/ -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=true -target_file_size_base=655 -compression_type=none ```run till convergence ``` ./db_bench -seed=1678564177044286 -use_existing_db=true -db=/dev/shm/testdb -benchmarks=readrandom[-X60] -statistics=true -num=1000000 -disable_auto_compactions=true -compression_type=none -bloom_bits=3 ``` Pre-change `readrandom [AVG 60 runs] : 21568 (± 248) ops/sec` Post-change (no regression, -0.3%) `readrandom [AVG 60 runs] : 21486 (± 236) ops/sec` **Compaction/Flush**run till convergence ``` ./db_bench -db=/dev/shm/testdb2/ -seed=1678564177044286 -benchmarks="fillseq[-X60]" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=false -target_file_size_base=655 -compression_type=none rocksdb.sst.read.micros COUNT : 33820 rocksdb.sst.read.flush.micros COUNT : 1800 rocksdb.sst.read.compaction.micros COUNT : 32020 ``` Pre-change `fillseq [AVG 46 runs] : 1391 (± 214) ops/sec; 0.7 (± 0.1) MB/sec` Post-change (no regression, ~-0.4%) `fillseq [AVG 46 runs] : 1385 (± 216) ops/sec; 0.7 (± 0.1) MB/sec` Reviewed By: ajkr Differential Revision: D44007011 Pulled By: hx235 fbshipit-source-id: a54c89e4846dfc9a135389edf3f3eedfea257132
2023-04-21 16:07:18 +00:00
const ReadOptions& read_options,
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
uint64_t read_offset, size_t read_size,
Statistics* statistics, Slice* slice, Buffer* buf,
Group rocksdb.sst.read.micros stat by different user read IOActivity + misc (#11444) Summary: **Context/Summary:** - Similar to https://github.com/facebook/rocksdb/pull/11288 but for user read such as `Get(), MultiGet(), DBIterator::XXX(), Verify(File)Checksum()`. - For this, I refactored some user-facing `MultiGet` calls in `TransactionBase` and various types of `DB` so that it does not call a user-facing `Get()` but `GetImpl()` for passing the `ReadOptions::io_activity` check (see PR conversation) - New user read stats breakdown are guarded by `kExceptDetailedTimers` since measurement shows they have 4-5% regression to the upstream/main. - Misc - More refactoring: with https://github.com/facebook/rocksdb/pull/11288, we complete passing `ReadOptions/IOOptions` to FS level. So we can now replace the previously [added](https://github.com/facebook/rocksdb/pull/9424) `rate_limiter_priority` parameter in `RandomAccessFileReader`'s `Read/MultiRead/Prefetch()` with `IOOptions::rate_limiter_priority` - Also, `ReadAsync()` call time is measured in `SST_READ_MICRO` now Pull Request resolved: https://github.com/facebook/rocksdb/pull/11444 Test Plan: - CI fake db crash/stress test - Microbenchmarking **Build** `make clean && ROCKSDB_NO_FBCODE=1 DEBUG_LEVEL=0 make -jN db_basic_bench` - google benchmark version: https://github.com/google/benchmark/commit/604f6fd3f4b34a84ec4eb4db81d842fa4db829cd - db_basic_bench_base: upstream - db_basic_bench_pr: db_basic_bench_base + this PR - asyncread_db_basic_bench_base: upstream + [db basic bench patch for IteratorNext](https://github.com/facebook/rocksdb/compare/main...hx235:rocksdb:micro_bench_async_read) - asyncread_db_basic_bench_pr: asyncread_db_basic_bench_base + this PR **Test** Get ``` TEST_TMPDIR=/dev/shm ./db_basic_bench_{null_stat|base|pr} --benchmark_filter=DBGet/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:1/negative_query:0/enable_filter:0/mmap:1/threads:1 --benchmark_repetitions=1000 ``` Result ``` Coming soon ``` AsyncRead ``` TEST_TMPDIR=/dev/shm ./asyncread_db_basic_bench_{base|pr} --benchmark_filter=IteratorNext/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:1/async_io:1/include_detailed_timers:0 --benchmark_repetitions=1000 > syncread_db_basic_bench_{base|pr}.out ``` Result ``` Base: 1956,1956,1968,1977,1979,1986,1988,1988,1988,1990,1991,1991,1993,1993,1993,1993,1994,1996,1997,1997,1997,1998,1999,2001,2001,2002,2004,2007,2007,2008, PR (2.3% regression, due to measuring `SST_READ_MICRO` that wasn't measured before): 1993,2014,2016,2022,2024,2027,2027,2028,2028,2030,2031,2031,2032,2032,2038,2039,2042,2044,2044,2047,2047,2047,2048,2049,2050,2052,2052,2052,2053,2053, ``` Reviewed By: ajkr Differential Revision: D45918925 Pulled By: hx235 fbshipit-source-id: 58a54560d9ebeb3a59b6d807639692614dad058a
2023-08-09 00:26:50 +00:00
AlignedBuf* aligned_buf);
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
static Status VerifyBlob(const Slice& record_slice, const Slice& user_key,
uint64_t value_size);
static Status UncompressBlobIfNeeded(const Slice& value_slice,
CompressionType compression_type,
MemoryAllocator* allocator,
SystemClock* clock,
Statistics* statistics,
std::unique_ptr<BlobContents>* result);
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
std::unique_ptr<RandomAccessFileReader> file_reader_;
uint64_t file_size_;
CompressionType compression_type_;
SystemClock* clock_;
Statistics* statistics_;
Introduce a blob file reader class (#7461) Summary: The patch adds a class called `BlobFileReader` that can be used to retrieve blobs using the information available in blob references (e.g. blob file number, offset, and size). This will come in handy when implementing blob support for `Get`, `MultiGet`, and iterators, and also for compaction/garbage collection. When a `BlobFileReader` object is created (using the factory method `Create`), it first checks whether the specified file is potentially valid by comparing the file size against the combined size of the blob file header and footer (files smaller than the threshold are considered malformed). Then, it opens the file, and reads and verifies the header and footer. The verification involves magic number/CRC checks as well as checking for unexpected header/footer fields, e.g. incorrect column family ID or TTL blob files. Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression type passed by the caller (because of the presence of the header and footer, the specified offset cannot be too close to the start/end of the file; also, the compression type has to match the one in the blob file header), and retrieves and potentially verifies and uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set, `BlobFileReader` reads the blob record header as well (as opposed to just the blob itself) and verifies the key/value size, the key itself, as well as the CRC of the blob record header and the key/value pair. In addition, the patch exposes the compression type from `BlobIndex` (both using an accessor and via `DebugString`), and adds a blob file read latency histogram to `InternalStats` that can be used with `BlobFileReader`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D23999219 Pulled By: ltamasi fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 22:43:23 +00:00
};
} // namespace ROCKSDB_NAMESPACE