github.com/cockroachdb/pebble@v0.0.0-20231214172447-ab4952c5f87b/objstorage/objstorageprovider/objiotracing/obj_io_tracing.go (about)

     1  // Copyright 2023 The LevelDB-Go and Pebble Authors. All rights reserved. Use
     2  // of this source code is governed by a BSD-style license that can be found in
     3  // the LICENSE file.
     4  
     5  package objiotracing
     6  
     7  import "github.com/cockroachdb/pebble/internal/base"
     8  
     9  // OpType indicates the type of operation.
    10  type OpType uint8
    11  
    12  // OpType values.
    13  const (
    14  	ReadOp OpType = iota
    15  	WriteOp
    16  	// RecordCacheHitOp happens when a read is satisfied from the block cache. See
    17  	// objstorage.ReadHandle.RecordCacheHit().
    18  	RecordCacheHitOp
    19  	// SetupForCompactionOp is a "meta operation" that configures a read handle
    20  	// for large sequential reads. See objstorage.ReadHandle.SetupForCompaction().
    21  	SetupForCompactionOp
    22  )
    23  
    24  // Reason indicates the higher-level context of the operation.
    25  type Reason uint8
    26  
    27  // Reason values.
    28  const (
    29  	UnknownReason Reason = iota
    30  	ForFlush
    31  	ForCompaction
    32  	ForIngestion
    33  	// TODO(radu): add ForUserFacing.
    34  )
    35  
    36  // BlockType indicates the type of data block relevant to an operation.
    37  type BlockType uint8
    38  
    39  // BlockType values.
    40  const (
    41  	UnknownBlock BlockType = iota
    42  	DataBlock
    43  	ValueBlock
    44  	FilterBlock
    45  	MetadataBlock
    46  )
    47  
    48  // Event is the on-disk format of a tracing event. It is exported here so that
    49  // trace processing tools can use it by importing this package.
    50  type Event struct {
    51  	// Event start time as a Unix time (see time.Time.StartUnixNano()).
    52  	// Note that recorded events are not necessarily ordered by time - this is
    53  	// because separate event "streams" use local buffers (for performance).
    54  	StartUnixNano int64
    55  	Op            OpType
    56  	Reason        Reason
    57  	BlockType     BlockType
    58  	// LSM level plus one (with 0 indicating unknown level).
    59  	LevelPlusOne uint8
    60  	// Hardcoded padding so that struct layout doesn't depend on architecture.
    61  	_       uint32
    62  	FileNum base.FileNum
    63  	// HandleID is a unique identifier corresponding to an objstorage.ReadHandle;
    64  	// only set for read operations performed through a ReadHandle.
    65  	HandleID uint64
    66  	Offset   int64
    67  	Size     int64
    68  }