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// META: title=Blob Stream
// META: script=../support/Blob.js
// META: script=/common/gc.js
'use strict';
// Helper function that triggers garbage collection while reading a chunk
// if perform_gc is true.
async function read_and_gc(reader, perform_gc) {
// Passing Uint8Array for byte streams; non-byte streams will simply ignore it
const read_promise = reader.read(new Uint8Array(64));
if (perform_gc) {
await garbageCollect();
}
return read_promise;
}
// Takes in a ReadableStream and reads from it until it is done, returning
// an array that contains the results of each read operation. If perform_gc
// is true, garbage collection is triggered while reading every chunk.
async function read_all_chunks(stream, { perform_gc = false, mode } = {}) {
assert_true(stream instanceof ReadableStream);
assert_true('getReader' in stream);
const reader = stream.getReader({ mode });
assert_true('read' in reader);
let read_value = await read_and_gc(reader, perform_gc);
let out = [];
let i = 0;
while (!read_value.done) {
for (let val of read_value.value) {
out[i++] = val;
}
read_value = await read_and_gc(reader, perform_gc);
}
return out;
}
promise_test(async () => {
const blob = new Blob(["PASS"]);
const stream = blob.stream();
const chunks = await read_all_chunks(stream);
for (let [index, value] of chunks.entries()) {
assert_equals(value, "PASS".charCodeAt(index));
}
}, "Blob.stream()")
promise_test(async () => {
const blob = new Blob();
const stream = blob.stream();
const chunks = await read_all_chunks(stream);
assert_array_equals(chunks, []);
}, "Blob.stream() empty Blob")
promise_test(async () => {
const input_arr = [8, 241, 48, 123, 151];
const typed_arr = new Uint8Array(input_arr);
const blob = new Blob([typed_arr]);
const stream = blob.stream();
const chunks = await read_all_chunks(stream);
assert_array_equals(chunks, input_arr);
}, "Blob.stream() non-unicode input")
promise_test(async() => {
const input_arr = [8, 241, 48, 123, 151];
const typed_arr = new Uint8Array(input_arr);
let blob = new Blob([typed_arr]);
const stream = blob.stream();
blob = null;
await garbageCollect();
const chunks = await read_all_chunks(stream, { perform_gc: true });
assert_array_equals(chunks, input_arr);
}, "Blob.stream() garbage collection of blob shouldn't break stream " +
"consumption")
promise_test(async() => {
const input_arr = [8, 241, 48, 123, 151];
const typed_arr = new Uint8Array(input_arr);
let blob = new Blob([typed_arr]);
const chunksPromise = read_all_chunks(blob.stream());
// It somehow matters to do GC here instead of doing `perform_gc: true`
await garbageCollect();
assert_array_equals(await chunksPromise, input_arr);
}, "Blob.stream() garbage collection of stream shouldn't break stream " +
"consumption")
promise_test(async () => {
const input_arr = [8, 241, 48, 123, 151];
const typed_arr = new Uint8Array(input_arr);
let blob = new Blob([typed_arr]);
const stream = blob.stream();
const chunks = await read_all_chunks(stream, { mode: "byob" });
assert_array_equals(chunks, input_arr);
}, "Reading Blob.stream() with BYOB reader")