/* Copyright 2022 Erigon contributors 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. */ package bptree import ( "bufio" "encoding/binary" "fmt" "io" "sort" ) type KeyFactory interface { NewUniqueKeyValues(reader *bufio.Reader) KeyValues NewUniqueKeys(reader *bufio.Reader) Keys } type KeyBinaryFactory struct { keySize int } func NewKeyBinaryFactory(keySize int) KeyFactory { return &KeyBinaryFactory{keySize: keySize} } func (factory *KeyBinaryFactory) NewUniqueKeyValues(reader *bufio.Reader) KeyValues { kvPairs := factory.readUniqueKeyValues(reader) sort.Sort(kvPairs) return kvPairs } func (factory *KeyBinaryFactory) NewUniqueKeys(reader *bufio.Reader) Keys { keys := factory.readUniqueKeys(reader) sort.Sort(keys) return keys } func (factory *KeyBinaryFactory) readUniqueKeyValues(reader *bufio.Reader) KeyValues { kvPairs := KeyValues{make([]*Felt, 0), make([]*Felt, 0)} keyRegistry := make(map[Felt]bool) buffer := make([]byte, BufferSize) for { bytes_read, err := reader.Read(buffer) ensure(err == nil || err == io.EOF, fmt.Sprintf("readUniqueKeyValues: read error %s\n", err)) if err == io.EOF { break } key_bytes_count := factory.keySize * (bytes_read / factory.keySize) duplicated_keys := 0 for i := 0; i < key_bytes_count; i += factory.keySize { key := factory.readKey(buffer, i) if _, duplicated := keyRegistry[key]; duplicated { duplicated_keys++ continue } keyRegistry[key] = true value := key // Shortcut: value equal to key kvPairs.keys = append(kvPairs.keys, &key) kvPairs.values = append(kvPairs.values, &value) } } return kvPairs } func (factory *KeyBinaryFactory) readUniqueKeys(reader *bufio.Reader) Keys { keys := make(Keys, 0) keyRegistry := make(map[Felt]bool) buffer := make([]byte, BufferSize) for { bytes_read, err := reader.Read(buffer) if err == io.EOF { break } key_bytes_count := factory.keySize * (bytes_read / factory.keySize) duplicated_keys := 0 for i := 0; i < key_bytes_count; i += factory.keySize { key := factory.readKey(buffer, i) if _, duplicated := keyRegistry[key]; duplicated { duplicated_keys++ continue } keyRegistry[key] = true keys = append(keys, Felt(key)) } } return keys } func (factory *KeyBinaryFactory) readKey(buffer []byte, offset int) Felt { keySlice := buffer[offset : offset+factory.keySize] switch factory.keySize { case 1: return Felt(keySlice[0]) case 2: return Felt(binary.BigEndian.Uint16(keySlice)) case 4: return Felt(binary.BigEndian.Uint32(keySlice)) default: return Felt(binary.BigEndian.Uint64(keySlice)) } }