Method addStack

deps/v8/tools/profview/profile-utils.js:444–501

(file, tickIndex)

  }

  addStack(file, tickIndex) {
    if (!this.functionCodeId) return;

    let { tm : timestamp, vm : vmState, s : stack } = file.ticks[tickIndex];
    let functionCode = file.code[this.functionCodeId];

    // Find if the function is on the stack, and its position on the stack,
    // ignoring any filtered entries.
    let stackCode = undefined;
    let functionPosInStack = -1;
    let filteredI = 0;
    for (let i = 0; i < stack.length - 1; i += 2) {
      let codeId = stack[i];
      let code = codeId >= 0 ? file.code[codeId] : undefined;
      let type = code ? code.type : undefined;
      let kind = code ? code.kind : undefined;
      if (!this.filter(type, kind)) continue;

      // Match other instances of the same function (e.g. unoptimised, various
      // different optimised versions).
      if (codeEquals(code, functionCode, true)) {
        functionPosInStack = filteredI;
        stackCode = code;
        break;
      }
      filteredI++;
    }

    if (functionPosInStack >= 0) {
      let stackKind = resolveCodeKindAndVmState(stackCode, vmState);

      let codeIsTopOfStack = (functionPosInStack === 0);

      if (this.currentBlock !== null) {
        this.currentBlock.end = timestamp;

        if (codeIsTopOfStack === this.currentBlock.topOfStack
          && stackKind === this.currentBlock.kind) {
          // If we haven't changed the stack top or the function kind, then
          // we're happy just extending the current block and not starting
          // a new one.
          return;
        }
      }

      // Start a new block at the current timestamp.
      this.currentBlock = {
        start: timestamp,
        end: timestamp,
        code: stackCode,
        kind: stackKind,
        topOfStack: codeIsTopOfStack
      };
      this.blocks.push(this.currentBlock);
    } else {
      this.currentBlock = null;
    }
  }