can1357
4210727227
- Added V8 `.cpuprofile` parser and bottleneck summary generation utilities. - Integrated profile summary rendering into the read tool execution. - Refactored profile rendering machinery into shared tree utilities. - Added comprehensive unit and integration tests for cpuprofile parsing and read tool dispatch.
112 lines
4.1 KiB
TypeScript
112 lines
4.1 KiB
TypeScript
/**
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* Shared display-tree machinery for profile summaries (macOS `sample` reports,
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* V8 `.cpuprofile` files). Callers build {@link ProfileNode} trees with a
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* domain-specific metric (on-CPU samples, self microseconds, …); this module
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* merges same-key siblings, flattens direct recursion, collapses pass-through
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* chains, and renders the pruned hot-path tree.
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*/
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/** Display node: merged, recursion-flattened mirror of a profile subtree. */
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export interface ProfileNode {
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/** Merge/recursion identity (demangled symbol, function@call-site, …). */
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key: string;
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/** Human-readable label; recursion and truncation decorations are applied at render time. */
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label: string;
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/** Inclusive metric for this subtree (on-CPU samples, self µs, …); drives pruning and display. */
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value: number;
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/** Levels of direct recursion flattened into this node. */
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recursion: number;
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children: ProfileNode[];
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}
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/** Labels longer than this are head-truncated (huge C++ templates, data URLs). */
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const MAX_LABEL_CHARS = 160;
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/** Merge `b` into `a` (same key), combining values and child lists. */
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export function mergeInto(a: ProfileNode, b: ProfileNode): void {
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a.value += b.value;
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a.recursion = Math.max(a.recursion, b.recursion);
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for (const child of b.children) {
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const existing = a.children.find(c => c.key === child.key);
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if (existing) mergeInto(existing, child);
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else a.children.push(child);
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}
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}
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/**
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* Flatten direct recursion: children carrying the node's own key are dissolved
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* into it (their children promoted and merged), so a 15-deep recursive spine
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* renders as one annotated node.
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*/
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export function flattenRecursion(node: ProfileNode): void {
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while (node.children.some(child => child.key === node.key)) {
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node.recursion++;
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const next: ProfileNode[] = [];
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for (const child of node.children) {
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const promoted = child.key === node.key ? child.children : [child];
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for (const item of promoted) {
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const existing = next.find(c => c.key === item.key);
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if (existing) mergeInto(existing, item);
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else next.push(item);
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}
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}
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node.children = next;
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}
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}
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/** `n` as a percentage of `total`, one decimal (`"12.3%"`); `"0%"` when total is empty. */
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export function formatPct(n: number, total: number): string {
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if (total <= 0) return "0%";
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return `${((100 * n) / total).toFixed(1)}%`;
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}
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/** Options for {@link renderProfileNode}. */
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export interface RenderTreeContext {
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out: string[];
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/** Denominator for percentage annotations. */
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total: number;
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/** Minimum subtree value a child needs to stay visible. */
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minValue: number;
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/** Format a metric value for the left column. */
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formatValue: (value: number) => string;
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/** Left-column width (characters) for formatted values. */
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valueWidth: number;
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}
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function decoratedLabel(node: ProfileNode): string {
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let label = node.label.length > MAX_LABEL_CHARS ? `${node.label.slice(0, MAX_LABEL_CHARS - 1)}…` : node.label;
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if (node.recursion > 0) label += ` [recursive ×${node.recursion + 1}]`;
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return label;
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}
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/**
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* Render one hot-path subtree: pass-through chains (single kept child, no own
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* contribution above `minValue`) collapse into a single `a › b › c` line, and
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* children below `minValue` are pruned.
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*/
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export function renderProfileNode(node: ProfileNode, indent: number, ctx: RenderTreeContext): void {
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const chain: ProfileNode[] = [node];
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let cur = node;
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for (;;) {
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flattenRecursion(cur);
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if (cur.recursion > 0) break;
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const kept = cur.children.filter(child => child.value >= ctx.minValue);
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if (kept.length !== 1 || cur.value - kept[0].value >= ctx.minValue) break;
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cur = kept[0];
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chain.push(cur);
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}
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flattenRecursion(cur);
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const labels = chain.map(decoratedLabel);
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const path =
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labels.length <= 4
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? labels.join(" › ")
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: `${labels[0]} › ⋯${labels.length - 2} frames⋯ › ${labels[labels.length - 1]}`;
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const value = ctx.formatValue(chain[0].value).padStart(ctx.valueWidth);
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const pct = formatPct(chain[0].value, ctx.total).padStart(6);
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ctx.out.push(`${value} ${pct} ${" ".repeat(indent)}${path}`);
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const kept = cur.children.filter(child => child.value >= ctx.minValue).sort((a, b) => b.value - a.value);
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for (const child of kept) renderProfileNode(child, indent + 1, ctx);
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}
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