github.com/dominant-strategies/go-quai@v0.28.2/ethdb/batch.go (about)

     1  // Copyright 2018 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package ethdb
    18  
    19  // IdealBatchSize defines the size of the data batches should ideally add in one
    20  // write.
    21  const IdealBatchSize = 100 * 1024
    22  
    23  // Batch is a write-only database that commits changes to its host database
    24  // when Write is called. A batch cannot be used concurrently.
    25  type Batch interface {
    26  	KeyValueWriter
    27  
    28  	// ValueSize retrieves the amount of data queued up for writing.
    29  	ValueSize() int
    30  
    31  	// Write flushes any accumulated data to disk.
    32  	Write() error
    33  
    34  	// Reset resets the batch for reuse.
    35  	Reset()
    36  
    37  	// Replay replays the batch contents.
    38  	Replay(w KeyValueWriter) error
    39  }
    40  
    41  // Batcher wraps the NewBatch method of a backing data store.
    42  type Batcher interface {
    43  	// NewBatch creates a write-only database that buffers changes to its host db
    44  	// until a final write is called.
    45  	NewBatch() Batch
    46  }
    47  
    48  // HookedBatch wraps an arbitrary batch where each operation may be hooked into
    49  // to monitor from black box code.
    50  type HookedBatch struct {
    51  	Batch
    52  
    53  	OnPut    func(key []byte, value []byte) // Callback if a key is inserted
    54  	OnDelete func(key []byte)               // Callback if a key is deleted
    55  }
    56  
    57  // Put inserts the given value into the key-value data store.
    58  func (b HookedBatch) Put(key []byte, value []byte) error {
    59  	if b.OnPut != nil {
    60  		b.OnPut(key, value)
    61  	}
    62  	return b.Batch.Put(key, value)
    63  }
    64  
    65  // Delete removes the key from the key-value data store.
    66  func (b HookedBatch) Delete(key []byte) error {
    67  	if b.OnDelete != nil {
    68  		b.OnDelete(key)
    69  	}
    70  	return b.Batch.Delete(key)
    71  }