ketraterm-render-cache/io.github.ketraterm.render.cache/TerminalRenderCache

TerminalRenderCache

class TerminalRenderCache(columns: Int, rows: Int, rowCapacityReserve: Int) : TerminalRenderFrameConsumer

Caller-owned primitive cache for render frames.

This cache consumes TerminalRenderFrameReader and stores copied primitive row data after the frame callback returns. It deliberately contains no backend-specific glyph runs, font state, paint objects, selection model, or UI timer logic. Swing, Compose, and other renderers can build their local layout and paint caches from this primitive data.

Cell and row planes may have spare capacity when rowCapacityReserve is non-zero. Only the prefix addressed by columns and rows is part of the current frame. The reserve lets renderers change a viewport's logical row count, for example while smooth-scroll overscan is active, without replacing the primitive arrays in the frame-update hot path.

Parameters

columns

initial cache width in cells.

rows

initial cache height in rows.

rowCapacityReserve

spare rows retained whenever primitive storage is allocated; must be non-negative.

Constructors

TerminalRenderCache

constructor(columns: Int, rows: Int, rowCapacityReserve: Int)

constructor(columns: Int, rows: Int)

Creates a cache whose primitive planes exactly fit its initial shape.

Properties

var activeBuffer: TerminalRenderBufferKind

Last copied active buffer kind.

var attrWords: LongArray

Copied primary public render attribute words in row-major order.

clusterCodepoints

var clusterCodepoints: IntArray

Packed codepoint storage referenced by clusterRefs.

var clusterRefs: LongArray

Copied cluster references in row-major order. Zero means no cluster; other values pack a codepoint offset in the high 32 bits and a codepoint length in the low 32 bits.

var codeWords: IntArray

Copied code words in row-major order. See TerminalRenderFrame.copyLine.

var columns: Int

Cached visible width in cells.

val cursor: TerminalRenderCursor?

Convenience cursor snapshot for tests and compatibility callers.

var cursorBlinking: Boolean

Last copied cursor blinking mode.

cursorChangedOnLastUpdate

var cursorChangedOnLastUpdate: Boolean

Whether the most recent updateFrom call changed the cursor state.

var cursorColumn: Int

Last copied cursor column.

cursorGeneration

var cursorGeneration: Long

Last copied cursor generation.

var cursorRow: Int

Last copied cursor row.

var cursorShape: TerminalRenderCursorShape

Last copied cursor shape.

var cursorVisible: Boolean

Last copied cursor visibility.

var discardedCount: Long

History lines discarded due to capacity wrapping since initialization.

var extraAttrWords: LongArray

Copied optional public extra-attribute words in row-major order.

var flags: IntArray

Copied public render cell flags in row-major order.

frameGeneration

var frameGeneration: Long

Last copied frame generation.

hasBlinkingText

var hasBlinkingText: Boolean

Whether any copied visible row contains SGR blinking text.

var historySize: Int

Retained history lines reported by the most recent frame.

var hyperlinkIds: IntArray

Copied optional hyperlink identifiers in row-major order. Zero means no hyperlink.

lineGenerations

var lineGenerations: LongArray

Cached per-row render generations.

lineHasBlinkingText

var lineHasBlinkingText: BooleanArray

Cached per-row marker for visible cells carrying the SGR blink attribute.

var lineIds: LongArray

Cached per-row stable logical line identities.

var lineWrapped: BooleanArray

Cached per-row soft-wrap flags.

var palette: TerminalColorPalette

Last copied color palette.

Cached visible height in rows.

scrollbackOffset

var scrollbackOffset: Int

Resolved scrollback offset copied by the most recent frame.

shapeChangedOnLastUpdate

var shapeChangedOnLastUpdate: Boolean

Whether the most recent updateFrom call changed the logical frame shape.

structureGeneration

var structureGeneration: Long

Last copied structure generation.

Functions

open override fun accept(frame: TerminalRenderFrame)

Copies row data, cursor state, active buffer kind, and color palette from the given frame into this cache's primitive storage.

fun clusterLength(ref: Long): Int

Returns the codepoint length encoded in ref.

fun clusterOffset(ref: Long): Int

Returns the codepoint offset encoded in ref.

fun clusterText(row: Int, column: Int): String?

Returns cluster text for diagnostics or compatibility callers.

fun rowOffset(row: Int): Int

Returns the row-major base offset for row in flattened cell planes.

fun updateFrom(reader: TerminalRenderFrameReader)

Copies changed rows and cursor state from reader.

fun updateFrom(reader: TerminalRenderFrameReader, scrollbackOffset: Int)

Copies changed rows and cursor state for a caller-owned scrollback viewport.

fun updateFrom(reader: TerminalRenderFrameReader, scrollbackOffset: Int, viewportRows: Int)

Copies changed rows and cursor state for a caller-owned scrollback viewport with optional render-only overscan rows.