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Interface modified mmap to fd

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Eli-Class
2026-01-29 09:24:48 +00:00
parent abc47d4909
commit c6e3eae22e
11 changed files with 727 additions and 1733 deletions
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168
lib/idx/protocol.ts
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@@ -1,106 +1,108 @@
// src/index-file/protocol.ts
import {
INDEX_MAGIC,
INDEX_VERSION,
INDEX_HEADER_SIZE,
INDEX_ENTRY_SIZE,
FLAG_VALID,
INDEX_MAGIC,
INDEX_VERSION,
INDEX_HEADER_SIZE,
INDEX_ENTRY_SIZE,
FLAG_VALID,
} from './constants.js';
import type { IndexHeader, IndexEntry } from './types.js';
const CRC_TABLE = new Uint32Array(256);
for (let i = 0; i < 256; i++) {
let c = i;
for (let j = 0; j < 8; j++) {
c = (c & 1) ? (0xEDB88320 ^ (c >>> 1)) : (c >>> 1);
}
CRC_TABLE[i] = c >>> 0;
let c = i;
for (let j = 0; j < 8; j++) {
c = (c & 1) ? (0xEDB88320 ^ (c >>> 1)) : (c >>> 1);
}
CRC_TABLE[i] = c >>> 0;
}
export function crc32(buf: Buffer, start = 0, end?: number): number {
let crc = 0xFFFFFFFF;
const len = end ?? buf.length;
for (let i = start; i < len; i++) {
crc = CRC_TABLE[(crc ^ buf[i]) & 0xFF] ^ (crc >>> 8);
}
return (~crc) >>> 0;
let crc = 0xFFFFFFFF;
const len = end ?? buf.length;
for (let i = start; i < len; i++) {
crc = CRC_TABLE[(crc ^ buf[i]) & 0xFF] ^ (crc >>> 8);
}
return (~crc) >>> 0;
}
export class IndexProtocol {
static createHeader(entryCount: number, magic = INDEX_MAGIC): Buffer {
const buf = Buffer.alloc(INDEX_HEADER_SIZE);
buf.write(magic, 0, 4, 'ascii');
buf.writeUInt32LE(INDEX_VERSION, 4);
buf.writeBigUInt64LE(BigInt(Date.now()) * 1000000n, 8);
buf.writeUInt32LE(INDEX_ENTRY_SIZE, 16);
buf.writeUInt32LE(entryCount, 20);
buf.writeUInt32LE(0, 24);
buf.writeBigUInt64LE(0n, 28);
buf.writeUInt32LE(0, 36);
return buf;
}
static createHeader(entryCount: number, autoIncrementSequence: boolean, magic = INDEX_MAGIC): Buffer {
const buf = Buffer.alloc(INDEX_HEADER_SIZE);
buf.write(magic, 0, 4, 'ascii');
buf.writeUInt32LE(INDEX_VERSION, 4);
buf.writeBigUInt64LE(BigInt(Date.now()) * 1000000n, 8);
buf.writeUInt32LE(INDEX_ENTRY_SIZE, 16);
buf.writeUInt32LE(entryCount, 20);
buf.writeUInt32LE(0, 24); // writtenCnt
buf.writeBigUInt64LE(0n, 28); // dataFileSize
buf.writeUInt32LE(0, 36); // latestSequence
buf.writeUInt8(autoIncrementSequence ? 1 : 0, 40); // autoIncrementSequence
return buf;
}
static readHeader(buf: Buffer): IndexHeader {
return {
magic: buf.toString('ascii', 0, 4),
version: buf.readUInt32LE(4),
createdAt: buf.readBigUInt64LE(8),
entrySize: buf.readUInt32LE(16),
entryCount: buf.readUInt32LE(20),
validCount: buf.readUInt32LE(24),
dataFileSize: buf.readBigUInt64LE(28),
lastSequence: buf.readUInt32LE(36),
reserved: buf.subarray(40, 64),
};
}
static readHeader(buf: Buffer): IndexHeader {
return {
magic: buf.toString('ascii', 0, 4),
version: buf.readUInt32LE(4),
createdAt: buf.readBigUInt64LE(8),
entrySize: buf.readUInt32LE(16),
entryCount: buf.readUInt32LE(20),
writtenCnt: buf.readUInt32LE(24),
dataFileSize: buf.readBigUInt64LE(28),
latestSequence: buf.readUInt32LE(36),
autoIncrementSequence: buf.readUInt8(40) === 1,
reserved: buf.subarray(41, 64),
};
}
static updateHeaderCounts(
buf: Buffer,
validCount: number,
dataFileSize: bigint,
lastSequence: number
): void {
buf.writeUInt32LE(validCount, 24);
buf.writeBigUInt64LE(dataFileSize, 28);
buf.writeUInt32LE(lastSequence, 36);
}
static updateHeaderCounts(
buf: Buffer,
writtenCnt: number,
dataFileSize: bigint,
latestSequence: number
): void {
buf.writeUInt32LE(writtenCnt, 24);
buf.writeBigUInt64LE(dataFileSize, 28);
buf.writeUInt32LE(latestSequence, 36);
}
static writeEntry(buf: Buffer, index: number, entry: Omit<IndexEntry, 'checksum'>): void {
const off = INDEX_HEADER_SIZE + index * INDEX_ENTRY_SIZE;
static writeEntry(buf: Buffer, index: number, entry: Omit<IndexEntry, 'checksum'>): void {
const off = INDEX_HEADER_SIZE + index * INDEX_ENTRY_SIZE;
buf.writeUInt32LE(entry.sequence, off);
buf.writeBigUInt64LE(entry.timestamp, off + 4);
buf.writeBigUInt64LE(entry.offset, off + 12);
buf.writeUInt32LE(entry.length, off + 20);
buf.writeUInt32LE(entry.flags | FLAG_VALID, off + 24);
buf.writeUInt32LE(entry.sequence, off);
buf.writeBigUInt64LE(entry.timestamp, off + 4);
buf.writeBigUInt64LE(entry.offset, off + 12);
buf.writeUInt32LE(entry.length, off + 20);
buf.writeUInt32LE(entry.flags | FLAG_VALID, off + 24);
const checksum = crc32(buf, off, off + 28);
buf.writeUInt32LE(checksum, off + 28);
}
const checksum = crc32(buf, off, off + 28);
buf.writeUInt32LE(checksum, off + 28);
}
static readEntry(buf: Buffer, index: number): IndexEntry | null {
const off = INDEX_HEADER_SIZE + index * INDEX_ENTRY_SIZE;
const flags = buf.readUInt32LE(off + 24);
static readEntry(buf: Buffer, index: number): IndexEntry | null {
const off = INDEX_HEADER_SIZE + index * INDEX_ENTRY_SIZE;
const flags = buf.readUInt32LE(off + 24);
if (!(flags & FLAG_VALID)) return null;
if (!(flags & FLAG_VALID)) return null;
return {
sequence: buf.readUInt32LE(off),
timestamp: buf.readBigUInt64LE(off + 4),
offset: buf.readBigUInt64LE(off + 12),
length: buf.readUInt32LE(off + 20),
flags,
checksum: buf.readUInt32LE(off + 28),
};
}
return {
sequence: buf.readUInt32LE(off),
timestamp: buf.readBigUInt64LE(off + 4),
offset: buf.readBigUInt64LE(off + 12),
length: buf.readUInt32LE(off + 20),
flags,
checksum: buf.readUInt32LE(off + 28),
};
}
static isValidEntry(buf: Buffer, index: number): boolean {
const off = INDEX_HEADER_SIZE + index * INDEX_ENTRY_SIZE;
const flags = buf.readUInt32LE(off + 24);
return (flags & FLAG_VALID) !== 0;
}
static isValidEntry(buf: Buffer, index: number): boolean {
const off = INDEX_HEADER_SIZE + index * INDEX_ENTRY_SIZE;
const flags = buf.readUInt32LE(off + 24);
return (flags & FLAG_VALID) !== 0;
}
static calcFileSize(entryCount: number): number {
return INDEX_HEADER_SIZE + INDEX_ENTRY_SIZE * entryCount;
}
}
static calcFileSize(entryCount: number): number {
return INDEX_HEADER_SIZE + INDEX_ENTRY_SIZE * entryCount;
}
}