Add RandomAccessMemory class for in-memory binary operations
This commit is contained in:
ImBenji
440
dart/lib/header.dart
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440
dart/lib/header.dart
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import 'dart:convert';
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import 'dart:io';
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import 'package:sweepstore/structures.dart';
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import 'helper_extensions.dart';
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void initialiseSweepstoreHeader(RandomAccessFile file, {
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int concurrentWorkers = 4,
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}) {
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SweepstoreHeaderWriter header = SweepstoreHeaderWriter(file);
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if (header.magicNumber == 'SWPT') {
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throw ArgumentError('Sweepstore file is already initialised.');
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}
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SweepstoreConcurrencyHeaderWriter concurrencyHeader = SweepstoreConcurrencyHeaderWriter(header);
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header.magicNumber = 'SWPT';
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header.version = "undefined";
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header.addressTablePointer = SweepstorePointer.nullptr;
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header.freeListCount = 0;
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header.isFreeListLifted = false;
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concurrencyHeader.masterIdentifier = 0;
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concurrencyHeader.masterHeartbeat = 0;
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concurrencyHeader.numberOfWorkers = concurrentWorkers;
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concurrencyHeader.isReadAllowed = false;
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for (int i = 0; i < concurrentWorkers; i++) {
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SweepstoreWorkerTicket ticket = concurrencyHeader[i];
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ticket.write(
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identifier: 0,
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workerHeartbeat: 0,
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ticketState: SweepstoreTicketState.FREE,
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ticketOperation: SweepstoreTicketOperation.NONE,
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keyHash: 0,
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writePointer: SweepstorePointer.nullptr,
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writeSize: 0,
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);
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}
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}
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class SweepstoreHeader {
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final RandomAccessFile _file;
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SweepstoreHeader(this._file);
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// Offset 0 - 4 bytes
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String get magicNumber {
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_file.setPositionSync(0);
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final bytes = _file.readSync(4);
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return String.fromCharCodes(bytes);
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}
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// Offset 4 - 12 bytes
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String get version {
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_file.setPositionSync(4);
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String version = utf8.decode(_file.readSync(12)).trim();
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return version;
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}
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// Offset 16 - 8 bytes
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SweepstorePointer get addressTablePointer {
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_file.setPositionSync(16);
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final address = _file.readIntSync(8);
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return SweepstorePointer(address);
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}
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// Offset 24 - 4 bytes
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int get freeListCount {
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_file.setPositionSync(24);
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int count = _file.readIntSync(4);
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return count;
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}
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// Offset 28 - 1 byte
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bool get isFreeListLifted {
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_file.setPositionSync(28);
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int flag = _file.readIntSync(1);
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return flag != 0;
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}
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SweepstoreConcurrencyHeader get concurrency => SweepstoreConcurrencyHeader(this);
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}
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class SweepstoreHeaderWriter extends SweepstoreHeader {
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SweepstoreHeaderWriter(RandomAccessFile file) : super(file);
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// Offset 0 - 4 bytes
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void set magicNumber(String value) {
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if (value.length != 4) {
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throw ArgumentError('Magic number must be exactly 4 characters long');
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}
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_file.setPositionSync(0);
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_file.writeFromSync(value.codeUnits);
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}
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// Offset 4 - 12 bytes
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void set version(String value) {
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if (value.length > 11) {
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throw ArgumentError('Version string must be at most 11 characters long');
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}
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_file.setPositionSync(4);
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_file.writeFromSync(utf8.encode(" " + value.padRight(11, ' ').substring(0, 11)));
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}
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// Offset 16 - 8 bytes
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void set addressTablePointer(SweepstorePointer pointer) {
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_file.setPositionSync(16);
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_file.writeIntSync(pointer.address, 8);
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}
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// Offset 24 - 4 bytes
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void set freeListCount(int value) {
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_file.setPositionSync(24);
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_file.writeIntSync(value, 4);
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}
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// Offset 28 - 1 byte
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void set isFreeListLifted(bool lifted) {
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_file.setPositionSync(28);
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_file.writeIntSync(lifted ? 1 : 0, 1);
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}
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}
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class SweepstoreConcurrencyHeader {
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final SweepstoreHeader _header;
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SweepstoreConcurrencyHeader(this._header);
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// Offset 29 - 8 bytes
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int get masterIdentifier {
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_header._file.setPositionSync(29);
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int id = _header._file.readIntSync(8);
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return id;
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}
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// Offset 37 - 4 bytes
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int get masterHeartbeat {
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_header._file.setPositionSync(37);
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int heartbeat = _header._file.readIntSync(4);
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return heartbeat;
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}
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// Offset 41 - 4 bytes
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int get numberOfWorkers {
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_header._file.setPositionSync(41);
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int numWorkers = _header._file.readIntSync(4);
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return numWorkers;
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}
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// Offset 45 - 1 byte
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bool get isReadAllowed {
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_header._file.setPositionSync(45);
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int flag = _header._file.readIntSync(1);
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return flag != 0;
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}
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SweepstoreWorkerTicket operator [](int ticketIndex) {
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if (ticketIndex < 0 || ticketIndex >= numberOfWorkers) {
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throw RangeError.index(ticketIndex, this, 'ticketIndex', null, numberOfWorkers);
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}
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return SweepstoreWorkerTicket(ticketIndex, this);
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}
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}
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class SweepstoreConcurrencyHeaderWriter extends SweepstoreConcurrencyHeader {
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SweepstoreConcurrencyHeaderWriter(SweepstoreHeader header) : super(header);
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// Offset 29 - 8 bytes
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void set masterIdentifier(int id) {
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_header._file.setPositionSync(29);
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_header._file.writeIntSync(id, 8);
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}
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// Offset 37 - 4 bytes
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void set masterHeartbeat(int heartbeat) {
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_header._file.setPositionSync(37);
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_header._file.writeIntSync(heartbeat, 4);
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}
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// Offset 41 - 4 bytes
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void set numberOfWorkers(int numWorkers) {
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_header._file.setPositionSync(41);
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_header._file.writeIntSync(numWorkers, 4);
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}
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// Offset 45 - 1 byte
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void set isReadAllowed(bool allowed) {
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_header._file.setPositionSync(45);
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_header._file.writeIntSync(allowed ? 1 : 0, 1);
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}
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}
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const int endOfStaticHeaderOffset = 46;
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class SweepstoreWorkerTicket {
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static const int _ticketSize = 30;
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final SweepstoreConcurrencyHeader _concurrencyHeader;
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final int ticketIndex;
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SweepstoreWorkerTicket(this.ticketIndex, this._concurrencyHeader);
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// All offsets are relative to the start of the workers ticket
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int get _baseOffset => endOfStaticHeaderOffset + (ticketIndex * _ticketSize);
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// Offset 0 - 4 bytes
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int get identifier {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset);
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int id = _concurrencyHeader._header._file.readIntSync(4);
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return id;
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}
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// Offset 4 - 4 bytes
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int get workerHeartbeat {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 4);
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int heartbeat = _concurrencyHeader._header._file.readIntSync(4);
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return heartbeat;
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}
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// Offset 8 - 1 byte
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SweepstoreTicketState get ticketState {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 8);
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int stateValue = _concurrencyHeader._header._file.readIntSync(1);
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return SweepstoreTicketState.values[stateValue];
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}
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// Offset 9 - 1 byte
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SweepstoreTicketOperation get ticketOperation {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 9);
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int operationValue = _concurrencyHeader._header._file.readIntSync(1);
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return SweepstoreTicketOperation.values[operationValue];
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}
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// Offset 10 - 8 bytes
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int get keyHash {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 10);
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int hash = _concurrencyHeader._header._file.readIntSync(8);
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return hash;
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}
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// Offset 18 - 8 bytes
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SweepstorePointer get writePointer {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 18);
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int address = _concurrencyHeader._header._file.readIntSync(8);
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return SweepstorePointer(address);
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}
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// Offset 26 - 4 bytes
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int get writeSize {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 26);
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int size = _concurrencyHeader._header._file.readIntSync(4);
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return size;
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}
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// Writer
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void write({
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int? identifier,
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int? workerHeartbeat,
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SweepstoreTicketState? ticketState,
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SweepstoreTicketOperation? ticketOperation,
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int? keyHash,
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SweepstorePointer? writePointer,
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int? writeSize,
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}) {
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try {
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_concurrencyHeader._header._file.lockSync(FileLock.blockingExclusive, _baseOffset, _baseOffset + _ticketSize);
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_concurrencyHeader._header._file.setPositionSync(_baseOffset);
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List<int> existingBuffer = _concurrencyHeader._header._file.readSync(_ticketSize);
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RandomAccessMemory buffer = RandomAccessMemory(existingBuffer);
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if (identifier != null) {
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buffer.setPositionSync(0);
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buffer.writeIntSync(identifier, 4);
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}
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if (workerHeartbeat != null) {
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buffer.setPositionSync(4);
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buffer.writeIntSync(workerHeartbeat, 4);
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}
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if (ticketState != null) {
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buffer.setPositionSync(8);
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buffer.writeIntSync(ticketState.index, 1);
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}
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if (ticketOperation != null) {
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buffer.setPositionSync(9);
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buffer.writeIntSync(ticketOperation.index, 1);
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}
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if (keyHash != null) {
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buffer.setPositionSync(10);
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buffer.writeIntSync(keyHash, 8);
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}
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if (writePointer != null) {
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buffer.setPositionSync(18);
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buffer.writeIntSync(writePointer.address, 8);
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}
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if (writeSize != null) {
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buffer.setPositionSync(26);
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buffer.writeIntSync(writeSize, 4);
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}
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_concurrencyHeader._header._file.setPositionSync(_baseOffset);
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_concurrencyHeader._header._file.writeFromSync(buffer.toUint8List());
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} finally {
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_concurrencyHeader._header._file.unlockSync(_baseOffset, _baseOffset + _ticketSize);
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}
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}
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bool writable() {
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try {
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_concurrencyHeader._header._file.lockSync(
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FileLock.blockingExclusive,
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_baseOffset,
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_baseOffset + _ticketSize
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);
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// Successfully locked - immediately unlock and return true
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_concurrencyHeader._header._file.unlockSync(_baseOffset, _baseOffset + _ticketSize);
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return true;
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} catch (e) {
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// Lock failed - already held by another process
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return false;
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}
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}
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}
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@deprecated
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class _SweepstoreWorkerTicket {
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static const int _ticketSize = 30;
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final SweepstoreConcurrencyHeader _concurrencyHeader;
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final int ticketIndex;
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_SweepstoreWorkerTicket(this.ticketIndex, this._concurrencyHeader);
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// All offsets are relative to the start of the workers ticket
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int get _baseOffset => endOfStaticHeaderOffset + (ticketIndex * _ticketSize);
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// Offset 0 - 4 bytes
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int get identifier {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset);
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int id = _concurrencyHeader._header._file.readIntSync(4);
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return id;
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}
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set identifier(int id) {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset);
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_concurrencyHeader._header._file.writeIntSync(id, 4);
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_concurrencyHeader._header._file.flushSync();
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}
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// Offset 4 - 4 bytes
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int get workerHeartbeat {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 4);
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int heartbeat = _concurrencyHeader._header._file.readIntSync(4);
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return heartbeat;
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}
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set workerHeartbeat(int heartbeat) {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 4);
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_concurrencyHeader._header._file.writeIntSync(heartbeat, 4);
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}
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// Offset 8 - 1 byte
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SweepstoreTicketState get ticketState {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 8);
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int stateValue = _concurrencyHeader._header._file.readIntSync(1);
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return SweepstoreTicketState.values[stateValue];
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}
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set ticketState(SweepstoreTicketState state) {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 8);
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_concurrencyHeader._header._file.writeIntSync(state.index, 1);
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_concurrencyHeader._header._file.flushSync();
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}
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// Offset 9 - 1 byte
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SweepstoreTicketOperation get ticketOperation {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 9);
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int operationValue = _concurrencyHeader._header._file.readIntSync(1);
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return SweepstoreTicketOperation.values[operationValue];
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}
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set ticketOperation(SweepstoreTicketOperation operation) {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 9);
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_concurrencyHeader._header._file.writeIntSync(operation.index, 1);
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}
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// Offset 10 - 8 bytes
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int get keyHash {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 10);
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int hash = _concurrencyHeader._header._file.readIntSync(8);
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return hash;
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}
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set keyHash(int hash) {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 10);
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_concurrencyHeader._header._file.writeIntSync(hash, 8);
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}
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// Offset 18 - 8 bytes
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SweepstorePointer get writePointer {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 18);
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int address = _concurrencyHeader._header._file.readIntSync(8);
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return SweepstorePointer(address);
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}
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set writePointer(SweepstorePointer pointer) {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 18);
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_concurrencyHeader._header._file.writeIntSync(pointer.address, 8);
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}
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// Offset 26 - 4 bytes
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int get writeSize {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 26);
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int size = _concurrencyHeader._header._file.readIntSync(4);
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return size;
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}
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set writeSize(int size) {
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_concurrencyHeader._header._file.setPositionSync(_baseOffset + 26);
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_concurrencyHeader._header._file.writeIntSync(size, 4);
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}
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// Helpers
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void lock() {
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_concurrencyHeader._header._file.lockSync(FileLock.exclusive, _baseOffset, _baseOffset + _ticketSize);
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}
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void unlock() {
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_concurrencyHeader._header._file.unlockSync(_baseOffset, _baseOffset + _ticketSize);
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}
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}
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