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TextRingBuffer

A bounded, in-memory store of UTF-8 encoded text lines.

Methods​

push()​

push(line, contentWasTruncated?): void;

Append a line. When the buffer is full the oldest segment, and therefore the oldest lines, are dropped.

Set contentWasTruncated when the caller has replaced truncated content with a line which fits, so TextRingBuffer.truncatedLines includes it.

Parameters​

ParameterType
linestring
contentWasTruncated?boolean

Returns​

void

size()​

size(): number;

The number of lines currently held in memory.

Returns​

number

byteLength()​

byteLength(): number;

The number of bytes currently held in memory.

Returns​

number

isEmpty()​

isEmpty(): boolean;

Whether no line is currently held in memory.

Returns​

boolean

droppedLines()​

droppedLines(): number;

The number of lines dropped since creation, either because they were evicted to make room, or because a segment was handed over to onSegmentSealed.

Returns​

number

truncatedLines()​

truncatedLines(): number;

The number of lines whose content was truncated, either by the buffer to fit a segment or by the caller before appending a replacement.

Returns​

number

clear()​

clear(): void;

Drop every line and reset all counters.

Returns​

void

flush()​

flush(): void;

Seal the active segment, i.e. hand the most recent lines, which are not full enough to be sealed on their own yet, to onSegmentSealed.

The segment is sealed for good, giving up its remaining capacity, so no line is ever reported twice. Flushing while the active segment holds no lines is a no-op, but flushing often means more, less full, segments and therefore fewer retained lines.

Returns​

void

toBlobParts()​

toBlobParts(): Uint8Array<ArrayBuffer>[];

The retained lines, oldest first, as byte views suitable for constructing a Blob without decoding or copying.

The views point directly into the buffer's memory, which is recycled as lines are evicted, so their content changes as more lines are pushed. Consumers which need a stable copy must either copy each view, or hand them to something which copies, e.g. the Blob constructor.

Returns​

Uint8Array<ArrayBuffer>[]

toString()​

toString(): string;

The retained lines, oldest first, decoded and concatenated.

Returns​

string

toArray()​

toArray(): string[];

The retained lines, oldest first, decoded into an array.

Returns​

string[]

[iterator]()​

iterator: IterableIterator<string>;

Iterates the retained lines, oldest first, decoding lazily.

Returns​

IterableIterator<string>