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/* Any copyright is dedicated to the Public Domain.
*/
const MAX_ARGUMENTS_TO_RECORD = 4;
const ZERO_ARGUMENTS_MAGIC = -2;
const EXPIRED_VALUES_MAGIC = -1;
const JSVAL_TYPE_DOUBLE = 0x00;
const JSVAL_TYPE_INT32 = 0x01;
const JSVAL_TYPE_BOOLEAN = 0x02;
const JSVAL_TYPE_UNDEFINED = 0x03;
const JSVAL_TYPE_NULL = 0x04;
const JSVAL_TYPE_MAGIC = 0x05;
const JSVAL_TYPE_STRING = 0x06;
const JSVAL_TYPE_SYMBOL = 0x07;
const JSVAL_TYPE_BIGINT = 0x09;
const JSVAL_TYPE_OBJECT = 0x0c;
const GETTER_SETTER_MAGIC = 0xf0;
const GENERIC_OBJECT_HAS_DENSE_ELEMENTS = 1;
const NUMBER_IS_OUT_OF_LINE_MAGIC = 0xf;
const MIN_INLINE_INT = -1;
const STRING_ENCODING_LATIN1 = 0;
const STRING_ENCODING_TWO_BYTE = 1;
const STRING_ENCODING_UTF8 = 2;
const OBJECT_KIND_NOT_IMPLEMENTED = 0;
const OBJECT_KIND_ARRAY_LIKE = 1;
const OBJECT_KIND_MAP_LIKE = 2;
const OBJECT_KIND_FUNCTION = 3;
const OBJECT_KIND_WRAPPED_PRIMITIVE_OBJECT = 4;
const OBJECT_KIND_GENERIC_OBJECT = 5;
const OBJECT_KIND_PROXY_OBJECT = 6;
const OBJECT_KIND_EXTERNAL = 7;
const MAX_COLLECTION_VALUES = 16;
const EXTERNAL_SUMMARY_EXPECTED_VERSION = 1;
const EXTERNAL_SUMMARY_KIND_OTHER = 0;
const EXTERNAL_SUMMARY_KIND_NODE = 1;
// const EXTERNAL_NODE_SUBKIND_OTHER = 0; (handled implicitly)
const EXTERNAL_NODE_SUBKIND_ELEMENT = 1;
const EXTERNAL_NODE_SUBKIND_ATTR = 2;
const EXTERNAL_NODE_SUBKIND_DOCUMENT = 3;
const EXTERNAL_NODE_SUBKIND_DOCUMENT_FRAGMENT = 4;
const EXTERNAL_NODE_SUBKIND_TEXT = 5;
const EXTERNAL_NODE_SUBKIND_COMMENT = 6;
class BufferReader {
#view;
#index;
constructor(buffer, index = 0) {
this.#view = new DataView(buffer);
this.#index = index;
}
setIndex(value) {
this.#index = value;
}
getIndex() {
return this.#index;
}
peekUint8() {
return this.#view.getUint8(this.#index);
}
readUint8() {
let result = this.#view.getUint8(this.#index);
this.#index += 1;
return result;
}
readUint16() {
let result = this.#view.getUint16(this.#index, true);
this.#index += 2;
return result;
}
readUint32() {
let result = this.#view.getUint32(this.#index, true);
this.#index += 4;
return result;
}
readInt8() {
let result = this.#view.getInt8(this.#index);
this.#index += 1;
return result;
}
readInt16() {
let result = this.#view.getInt16(this.#index, true);
this.#index += 2;
return result;
}
readInt32() {
let result = this.#view.getInt32(this.#index, true);
this.#index += 4;
return result;
}
readFloat64() {
let result = this.#view.getFloat64(this.#index, true);
this.#index += 8;
return result;
}
readString() {
let encodingAndLength = this.readUint16();
let length = encodingAndLength & ~(0b11 << 14);
let encoding = encodingAndLength >> 14;
if (length == 0) {
return "";
}
let result = "";
if (encoding == STRING_ENCODING_LATIN1) {
let decoder = new TextDecoder("latin1");
result = decoder.decode(
this.#view.buffer.slice(this.#index, this.#index + length)
);
this.#index += length;
} else if (encoding == STRING_ENCODING_UTF8) {
let decoder = new TextDecoder("utf-8");
result = decoder.decode(
this.#view.buffer.slice(this.#index, this.#index + length)
);
this.#index += length;
} else if (encoding == STRING_ENCODING_TWO_BYTE) {
let decoder = new TextDecoder("utf-16"); // this isn't quite right, is it? ugh.
let size = length * 2;
result = decoder.decode(
this.#view.buffer.slice(this.#index, this.#index + size)
);
this.#index += size;
}
return result;
}
}
function readArrayLikeSummary(result, reader, flags, depth, shapes) {
let shapeId = reader.readUint32();
let shape = shapes[shapeId];
if (!shape || shape.length <= 0) {
return;
}
result.class = shape[0];
let preview = {};
preview.kind = "ArrayLike";
preview.items = [];
preview.length = reader.readUint32();
if (depth < 1) {
for (let i = 0; i < preview.length && i < MAX_COLLECTION_VALUES; i++) {
if (reader.peekUint8() == JSVAL_TYPE_MAGIC) {
reader.readUint8();
continue;
}
let nestedSummary = readValueSummary(reader, depth + 1, shapes);
preview.items.push(nestedSummary);
}
}
result.preview = preview;
}
function readFunctionSummary(result, reader) {
result.class = "Function";
result.name = reader.readString();
result.parameterNames = [];
let numParameterNames = reader.readUint32();
for (let i = 0; i < numParameterNames && i < MAX_COLLECTION_VALUES; i++) {
result.parameterNames.push(reader.readString());
}
}
function readMapLikeSummary(result, reader, flags, depth, shapes) {
let shapeId = reader.readUint32();
let shape = shapes[shapeId];
if (!shape || shape.length <= 0) {
return;
}
result.class = shape[0];
let preview = {};
preview.kind = "MapLike";
preview.entries = [];
preview.size = reader.readUint32();
if (depth < 1) {
for (let i = 0; i < preview.length && i < MAX_COLLECTION_VALUES; i++) {
let keySummary = readValueSummary(reader, depth + 1, shapes);
let valueSummary = readValueSummary(reader, depth + 1, shapes);
preview.entries.push([
{
configurable: true,
enumerable: true,
writable: true,
value: keySummary,
},
{
configurable: true,
enumerable: true,
writable: true,
value: valueSummary,
},
]);
}
}
result.preview = preview;
}
function readGenericObjectSummary(result, reader, flags, depth, shapes) {
let shapeId = reader.readUint32();
let shape = shapes[shapeId];
if (!shape || shape.length <= 0) {
return;
}
result.class = shape[0];
let preview = {};
preview.kind = "Object";
let hasDenseElements = !!(flags & GENERIC_OBJECT_HAS_DENSE_ELEMENTS);
let ownProperties = {};
let ownPropertiesLength = reader.readUint32();
if (depth < 1) {
for (let i = 1; i < shape.length && i <= MAX_COLLECTION_VALUES; i++) {
let header = reader.peekUint8();
let id = shape[i];
let desc = {
configurable: true,
enumerable: true,
};
if (header == GETTER_SETTER_MAGIC) {
reader.readUint8();
desc.get = readValueSummary(reader, depth + 1, shapes);
desc.set = readValueSummary(reader, depth + 1, shapes);
} else {
let nestedSummary = readValueSummary(reader, depth + 1, shapes);
desc.writable = true;
desc.value = nestedSummary;
}
ownProperties[id] = desc;
}
}
if (hasDenseElements) {
let elementsLength = reader.readUint32();
if (depth < 1) {
for (let i = 0; i < elementsLength && i < MAX_COLLECTION_VALUES; i++) {
if (reader.peekUint8() == JSVAL_TYPE_MAGIC) {
reader.readUint8();
continue;
}
ownPropertiesLength++;
let nestedSummary = readValueSummary(reader, depth + 1, shapes);
ownProperties[i] = {
configurable: true,
enumerable: true,
writable: true,
value: nestedSummary,
};
}
}
}
preview.ownProperties = ownProperties;
preview.ownPropertiesLength = ownPropertiesLength;
result.preview = preview;
}
function readClassFromShape(result, reader, shapes) {
let shapeId = reader.readUint32();
let shape = shapes[shapeId];
if (!shape || shape.length <= 0) {
return;
}
result.class = shape[0];
}
function readNodeSummary(result, reader, depth, shapes) {
let preview = {};
preview.kind = "DOMNode";
preview.nodeType = reader.readUint16();
preview.nodeName = reader.readString().toLowerCase();
let subkindAndIsConnected = reader.readUint8();
let subkind = subkindAndIsConnected & ~(1 << 7);
preview.isConnected = subkindAndIsConnected >> 7;
if (subkind == EXTERNAL_NODE_SUBKIND_ELEMENT) {
preview.attributes = {};
preview.attributesLength = reader.readUint32();
for (
let i = 0;
i < preview.attributesLength && i < MAX_COLLECTION_VALUES;
i++
) {
let attrName = reader.readString();
let attrVal = reader.readString();
preview.attributes[attrName] = attrVal;
}
} else if (subkind == EXTERNAL_NODE_SUBKIND_ATTR) {
preview.value = reader.readString();
} else if (subkind == EXTERNAL_NODE_SUBKIND_DOCUMENT) {
preview.location = reader.readString();
} else if (subkind == EXTERNAL_NODE_SUBKIND_DOCUMENT_FRAGMENT) {
preview.childNodesLength = reader.readUint32();
if (depth < 1) {
preview.childNodes = [];
for (
let i = 0;
i < preview.childNodesLength && i < MAX_COLLECTION_VALUES;
i++
) {
preview.childNodes.push(readValueSummary(reader, depth + 1, shapes));
}
}
} else if (
subkind == EXTERNAL_NODE_SUBKIND_TEXT ||
subkind == EXTERNAL_NODE_SUBKIND_COMMENT
) {
preview.textContent = reader.readString();
}
result.preview = preview;
}
function readExternalObjectSummary(result, reader, depth, shapes) {
readClassFromShape(result, reader, shapes);
let startIndex = reader.getIndex();
let size = reader.readUint32();
try {
let version = reader.readUint8();
if (version != EXTERNAL_SUMMARY_EXPECTED_VERSION) {
return;
}
let kind = reader.readUint8();
if (kind == EXTERNAL_SUMMARY_KIND_OTHER) {
return;
}
switch (kind) {
case EXTERNAL_SUMMARY_KIND_NODE: {
readNodeSummary(result, reader, depth, shapes);
break;
}
default:
}
} finally {
reader.setIndex(startIndex + size);
}
}
function readObjectSummary(reader, flags, depth, shapes) {
let result = {
type: "object",
class: undefined,
ownPropertyLength: 0,
isError: false,
extensible: false,
sealed: false,
frozen: false,
};
let kind = reader.readUint8();
switch (kind) {
case OBJECT_KIND_NOT_IMPLEMENTED:
readClassFromShape(result, reader, shapes);
break;
case OBJECT_KIND_ARRAY_LIKE:
readArrayLikeSummary(result, reader, flags, depth, shapes);
break;
case OBJECT_KIND_MAP_LIKE:
readMapLikeSummary(result, reader, flags, depth, shapes);
break;
case OBJECT_KIND_FUNCTION:
readFunctionSummary(result, reader);
break;
case OBJECT_KIND_EXTERNAL:
readExternalObjectSummary(result, reader, depth, shapes);
break;
case OBJECT_KIND_WRAPPED_PRIMITIVE_OBJECT: {
result.wrappedValue = readValueSummary(reader, depth, shapes);
readGenericObjectSummary(result, reader, flags, depth, shapes);
break;
}
case OBJECT_KIND_GENERIC_OBJECT: {
readGenericObjectSummary(result, reader, flags, depth, shapes);
break;
}
case OBJECT_KIND_PROXY_OBJECT: {
readClassFromShape(result, reader, shapes);
result.preview = {
kind: "Object",
ownProperties: Object.create(null),
ownPropertiesLength: 0,
};
break;
}
default:
throw new Error("Bad object kind");
}
return result;
}
function readValueSummary(reader, depth, shapes) {
let header = reader.readUint8();
let type = header & 0x0f;
let flags = (header & 0xf0) >> 4;
switch (type) {
case JSVAL_TYPE_DOUBLE:
if (flags == NUMBER_IS_OUT_OF_LINE_MAGIC) {
let value = reader.readFloat64();
if (value === Infinity) {
return { type: "Infinity" };
} else if (value === -Infinity) {
return { type: "-Infinity" };
} else if (Number.isNaN(value)) {
return { type: "NaN" };
} else if (!value && 1 / value === -Infinity) {
return { type: "-0" };
}
return value;
}
return 0;
case JSVAL_TYPE_INT32:
if (flags == NUMBER_IS_OUT_OF_LINE_MAGIC) {
return reader.readInt32();
}
return flags + MIN_INLINE_INT;
case JSVAL_TYPE_BOOLEAN:
return !!flags;
case JSVAL_TYPE_NULL:
return { type: "null" };
case JSVAL_TYPE_UNDEFINED:
return { type: "undefined" };
case JSVAL_TYPE_SYMBOL:
return {
type: "symbol",
name: reader.readString(),
};
case JSVAL_TYPE_BIGINT:
return {
type: "BigInt",
text: reader.readString(),
};
case JSVAL_TYPE_STRING: {
return reader.readString();
}
case JSVAL_TYPE_OBJECT: {
return readObjectSummary(reader, flags, depth, shapes);
}
default:
throw new Error("Bad value type");
}
}
function getArgumentSummaries(valuesBuffer, shapes, valuesBufferIndex) {
if (valuesBufferIndex == ZERO_ARGUMENTS_MAGIC) {
return [];
}
if (valuesBufferIndex == EXPIRED_VALUES_MAGIC) {
return "<missing>";
}
let reader = new BufferReader(valuesBuffer, valuesBufferIndex);
let argc = reader.readUint32();
let args = new Array(argc);
for (let i = 0; i < argc && i < MAX_ARGUMENTS_TO_RECORD; i++) {
args[i] = readValueSummary(reader, 0, shapes);
}
return args;
}
export const ValueSummaryReader = { getArgumentSummaries };