Class: OpfsSpoolReader

Defined in: src/batteries/storage/opfs/index.ts:264

Reads an OPFS-backed file as a @nhtio/adk!SpoolReader.

Remarks

Constructor is not async — but the first method call awaits a private readiness promise that fetches the underlying File (and in eager mode, its contents). Subsequent calls reuse the cached state. This keeps construction call sites synchronous while still doing real I/O lazily.

All four SpoolReader methods on this reader return promises. The SpoolReader contract supports both sync and async return; consumers of SpooledArtifact handle either.

Implements

• SpoolReader

Constructors

Constructor

new OpfsSpoolReader(handle: OpfsFileHandle, opts?: OpfsSpoolReaderOptions): OpfsSpoolReader;

Defined in: src/batteries/storage/opfs/index.ts:270

Parameters

Parameter	Type
handle	OpfsFileHandle
opts	OpfsSpoolReaderOptions

Returns

OpfsSpoolReader

Methods

byteLength()

byteLength(): Promise<number>;

Defined in: src/batteries/storage/opfs/index.ts:303

Returns the total number of bytes in the underlying data.

Returns

Promise<number>

The byte length of the underlying data.

Remarks

Used for reporting and token-estimation purposes. Byte length is distinct from character length for multi-byte encodings.

Implementation of

SpoolReader.byteLength

---

describe()

describe():
  | ReaderDescriptor
  | undefined;

Defined in: src/batteries/storage/opfs/index.ts:328

Optionally emit a serialisable ReaderDescriptor so a @nhtio/adk!SpooledArtifact backed by this reader can round-trip through encode()/decode() as a handle.

Returns

| ReaderDescriptor | undefined

A tagged, serialisable handle, or undefined/absent when the reader cannot describe itself.

Remarks

Synchronous by contract — the encoder's [ENCODE_METHOD]() is synchronous and cannot await. The descriptor describes where the bytes live (a spool key, or an inlined string for in-memory readers) — never the live binding (Disk, OPFS root), which the matching resolver re-injects on decode. A reader that omits this method is treated as non-describable: line/text reads still work at runtime, the SpooledArtifact simply cannot be serialised, and encoding it throws @nhtio/adk!E_READER_NOT_DESCRIBABLE.

Implementation of

SpoolReader.describe

---

line()

line(index: number): Promise<string | undefined>;

Defined in: src/batteries/storage/opfs/index.ts:296

Returns the line at the given 0-based index, or undefined when out of range.

Parameters

Parameter	Type	Description
index	number	0-based line index.

Returns

Promise<string | undefined>

The raw line string (without trailing newline), or undefined.

Implementation of

SpoolReader.line

---

lineCount()

lineCount(): Promise<number>;

Defined in: src/batteries/storage/opfs/index.ts:308

Returns the total number of lines in the underlying data.

Returns

Promise<number>

The total line count.

Remarks

Required so consumers know when to stop iterating; the line count must remain stable for the lifetime of the reader.

Implementation of

SpoolReader.lineCount

---

readAll()

readAll(): Promise<string>;

Defined in: src/batteries/storage/opfs/index.ts:322

Returns the full underlying content as a single decoded string, byte-faithful to the source.

Returns

Promise<string>

Remarks

In eager mode the content is already cached at first-call load and this method is effectively a property access. In streaming mode there is no cache: the file is re-read (as a single File.text() call) on every invocation. Use SpooledArtifact.asString() judiciously on large streaming-mode artifacts.

Implementation of

SpoolReader.readAll

---

isOpfsSpoolReader()

static isOpfsSpoolReader(value: unknown): value is OpfsSpoolReader;

Defined in: src/batteries/storage/opfs/index.ts:292

Returns true if value is an OpfsSpoolReader instance.

Parameters

Parameter	Type	Description
value	unknown	The value to test.

Returns

value is OpfsSpoolReader

true when value is an OpfsSpoolReader instance.

Remarks

Uses @nhtio/adk!isInstanceOf for cross-realm safety.