@zenfs/core/dist/backends/single_buffer.d.ts

A filesystem, anywhere

import type { ArrayOf } from 'memium';
import type { UUID } from 'node:crypto';
import { BufferView } from 'utilium/buffer';
import type { UsageInfo } from '../internal/filesystem.js';
import { StoreFS } from './store/fs.js';
import { SyncMapTransaction, type SyncMapStore } from './store/map.js';
import type { Store } from './store/store.js';
type Lock = Disposable & (() => void);
declare const MetadataEntry_base: import("memium").StructConstructor<BufferView<any>>;
declare class MetadataEntry extends MetadataEntry_base {
    static name: string;
    /** Inode or data ID */
    accessor id: number;
    /** Reserved for 64-bit offset expansion */
    protected accessor offset_: number;
    /** Offset into the buffer the data is stored at. */
    accessor offset: number;
    /** The size of the data */
    accessor size: number;
    toString(): string;
}
declare const MetadataBlock_base: import("memium/decorators").StructFromTypedArray<Int32Array<ArrayBuffer>>;
/**
 * A block of metadata for a single-buffer file system.
 * This metadata maps IDs (for inodes and data) to actual offsets in the buffer.
 * This is done since IDs are not guaranteed to be sequential.
 */
export declare class MetadataBlock extends MetadataBlock_base<ArrayBufferLike> {
    static name: string;
    readonly ['constructor']: typeof MetadataBlock;
    private static readonly lockIndex;
    /**
     * The crc32c checksum for the metadata block.
     * @privateRemarks Keep this first!
     */
    accessor checksum: number;
    /** The (last) time this metadata block was updated */
    accessor timestamp: bigint;
    /** Offset to the previous metadata block */
    accessor previous_offset: number;
    protected _previous?: MetadataBlock;
    get previous(): MetadataBlock | undefined;
    /** Metadata entries. */
    accessor items: ArrayOf<MetadataEntry>;
    toString(long?: boolean): string;
    /**
     * If non-zero, this block is locked for writing.
     * Note a int32 is used for `Atomics.wait`
     */
    accessor locked: number;
    /**
     * Wait for the block to be unlocked.
     */
    waitUnlocked(depth?: number): void;
    lock(): Lock;
}
declare const SuperBlock_base: import("memium/decorators").StructFromTypedArray<BigUint64Array<ArrayBuffer>>;
/**
 * The super block structure for a single-buffer file system
 */
export declare class SuperBlock extends SuperBlock_base<ArrayBufferLike> {
    static name: string;
    readonly ['constructor']: typeof SuperBlock;
    constructor(...args: ConstructorParameters<typeof BigUint64Array<ArrayBufferLike>>);
    /**
     * The crc32c checksum for the super block.
     * @privateRemarks Keep this first!
     */
    accessor checksum: number;
    /** Signature for the superblock. */
    accessor magic: number;
    /** The version of the on-disk format */
    accessor version: number;
    /** Which format of `Inode` is used */
    accessor inode_format: number;
    /** Flags for the file system. Currently unused */
    accessor flags: number;
    /** The number of used bytes, including the super block and metadata */
    accessor used_bytes: bigint;
    /** The total size of the entire file system, including the super block and metadata */
    accessor total_bytes: bigint;
    /** A UUID for this file system */
    accessor uuid: Uint8Array;
    /**
     * The size in bytes of a metadata block.
     * Not currently configurable.
     */
    accessor metadata_block_size: number;
    /** Reserved for 64-bit offset expansion */
    protected accessor metadata_offset_: number;
    /** Offset of the current metadata block */
    accessor metadata_offset: number;
    metadata: MetadataBlock;
    /** An optional label for the file system */
    accessor label: Uint8Array;
    /** Padded to 256 bytes */
    accessor _padding: Uint8Array;
    /**
     * Rotate out the current metadata block.
     * Allocates a new metadata block, moves the current one to backup,
     * and updates used_bytes accordingly.
     * @returns the new metadata block
     */
    rotateMetadata(): MetadataBlock;
    /**
     * Checks to see if `length` bytes are unused, starting at `offset`.
     * @internal Not for external use!
     */
    isUnused(offset: number, length: number): boolean;
}
/**
 *
 * @category Stores and Transactions
 */
export declare class SingleBufferStore extends BufferView implements SyncMapStore {
    readonly flags: readonly [];
    readonly name = "sbfs";
    readonly type = 1935828595;
    get uuid(): UUID;
    protected superblock: SuperBlock;
    /**
     * @internal @hidden
     */
    protected readonly _view: DataView;
    protected readonly _u8: Uint8Array;
    constructor(...args: ConstructorParameters<typeof BufferView>);
    keys(): Iterable<number>;
    get(id: number): Uint8Array | undefined;
    set(id: number, data: Uint8Array): void;
    delete(id: number): void;
    protected _fs?: StoreFS<Store> | undefined;
    get fs(): StoreFS<Store> | undefined;
    set fs(fs: StoreFS<Store> | undefined);
    sync(): Promise<void>;
    usage(): UsageInfo;
    transaction(): SyncMapTransaction;
}
/**
 * Options for the `SingleBuffer` backend
 * @category Backends and Configuration
 */
export interface SingleBufferOptions {
    buffer: ArrayBufferLike | ArrayBufferView;
}
declare const _SingleBuffer: {
    readonly name: "SingleBuffer";
    readonly options: {
        readonly buffer: {
            readonly type: "object";
            readonly required: true;
        };
    };
    readonly create: (opt: SingleBufferOptions) => StoreFS<SingleBufferStore>;
};
type _SingleBuffer = typeof _SingleBuffer;
/**
 * A backend that uses a single buffer for storing data
 * @category Backends and Configuration
 */
export interface SingleBuffer extends _SingleBuffer {
}
/**
 * A backend that uses a single buffer for storing data
 * @category Backends and Configuration
 */
export declare const SingleBuffer: SingleBuffer;
export {};