Skip to content

Commit

Permalink
util: improve display of iterators and weak entries
Browse files Browse the repository at this point in the history 
This adds the number of not visible elements when inspecting iterators
while exceeding `maxArrayLength`.
It also fixes a edge case with `maxArrayLength` and the map.entries()
iterator. Now the whole entry will be visible instead of only the key
but not the value of the first entry.
Besides that it uses a slighly better algorithm that improves the
performance by skipping unnecessary steps.

PR-URL: #20961
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
  • Loading branch information
@BridgeAR @rvagg
BridgeAR authored and rvagg committed Aug 15, 2018
1 parent d95a22c commit b171fa2
Show file tree
Hide file tree
Showing 4 changed files with 89 additions and 70 deletions.
9 changes: 6 additions & 3 deletions lib/console.js
View file
Expand Up @@ -360,8 +360,11 @@ Console.prototype.table = function(tabularData, properties) {
const mapIter = isMapIterator(tabularData);
let isKeyValue = false;
let i = 0;
if (mapIter)
[ tabularData, isKeyValue ] = previewEntries(tabularData);
if (mapIter) {
const res = previewEntries(tabularData, true);
tabularData = res[0];
isKeyValue = res[1];
}

if (isKeyValue || isMap(tabularData)) {
const keys = [];
Expand Down Expand Up @@ -391,7 +394,7 @@ Console.prototype.table = function(tabularData, properties) {

const setIter = isSetIterator(tabularData);
if (setIter)
[ tabularData ] = previewEntries(tabularData);
tabularData = previewEntries(tabularData);

const setlike = setIter || (mapIter && !isKeyValue) || isSet(tabularData);
if (setlike) {
Expand Down
98 changes: 54 additions & 44 deletions lib/util.js
View file
Expand Up @@ -115,6 +115,10 @@ const meta = [
'', '', '', '', '', '', '', '', '', '',
'', '', '', '', '', '', '', '\\\\'
];
// Constants to map the iterator state.
const kWeak = 0;
const kIterator = 1;
const kMapEntries = 2;

const escapeFn = (str) => meta[str.charCodeAt(0)];

Expand Down Expand Up @@ -982,77 +986,83 @@ function formatMap(ctx, value, recurseTimes, keys) {
return output;
}

function formatWeakSet(ctx, value, recurseTimes, keys) {
function formatSetIterInner(ctx, value, recurseTimes, keys, entries, state) {
const maxArrayLength = Math.max(ctx.maxArrayLength, 0);
const [ entries ] = previewEntries(value).slice(0, maxArrayLength + 1);
const maxLength = Math.min(maxArrayLength, entries.length);
let output = new Array(maxLength);
for (var i = 0; i < maxLength; ++i)
output[i] = formatValue(ctx, entries[i], recurseTimes);
// Sort all entries to have a halfway reliable output (if more entries than
// retrieved ones exist, we can not reliably return the same output).
output = output.sort();
if (entries.length > maxArrayLength)
output.push('... more items');
if (state === kWeak) {
// Sort all entries to have a halfway reliable output (if more entries than
// retrieved ones exist, we can not reliably return the same output).
output = output.sort();
}
const remaining = entries.length - maxLength;
if (remaining > 0) {
output.push(`... ${remaining} more item${remaining > 1 ? 's' : ''}`);
}
for (i = 0; i < keys.length; i++)
output.push(formatProperty(ctx, value, recurseTimes, keys[i], 0));
return output;
}

function formatWeakMap(ctx, value, recurseTimes, keys) {
function formatMapIterInner(ctx, value, recurseTimes, keys, entries, state) {
const maxArrayLength = Math.max(ctx.maxArrayLength, 0);
const [ entries ] = previewEntries(value).slice(0, (maxArrayLength + 1) * 2);
// Entries exist as [key1, val1, key2, val2, ...]
const remainder = entries.length / 2 > maxArrayLength;
const len = entries.length / 2 - (remainder ? 1 : 0);
const len = entries.length / 2;
const remaining = len - maxArrayLength;
const maxLength = Math.min(maxArrayLength, len);
let output = new Array(maxLength);
for (var i = 0; i < maxLength; i++) {
let start = '';
let end = '';
let middle = ' => ';
let i = 0;
if (state === kMapEntries) {
start = '[ ';
end = ' ]';
middle = ', ';
}
for (; i < maxLength; i++) {
const pos = i * 2;
output[i] = `${formatValue(ctx, entries[pos], recurseTimes)} => ` +
formatValue(ctx, entries[pos + 1], recurseTimes);
output[i] = `${start}${formatValue(ctx, entries[pos], recurseTimes)}` +
`${middle}${formatValue(ctx, entries[pos + 1], recurseTimes)}${end}`;
}
if (state === kWeak) {
// Sort all entries to have a halfway reliable output (if more entries
// than retrieved ones exist, we can not reliably return the same output).
output = output.sort();
}
if (remaining > 0) {
output.push(`... ${remaining} more item${remaining > 1 ? 's' : ''}`);
}
// Sort all entries to have a halfway reliable output (if more entries than
// retrieved ones exist, we can not reliably return the same output).
output = output.sort();
if (remainder > 0)
output.push('... more items');
for (i = 0; i < keys.length; i++)
output.push(formatProperty(ctx, value, recurseTimes, keys[i], 0));
return output;
}

function zip2(list) {
const ret = Array(list.length / 2);
for (var i = 0; i < ret.length; ++i)
ret[i] = [list[2 * i], list[2 * i + 1]];
return ret;
function formatWeakSet(ctx, value, recurseTimes, keys) {
const entries = previewEntries(value);
return formatSetIterInner(ctx, value, recurseTimes, keys, entries, kWeak);
}

function formatCollectionIterator(ctx, value, recurseTimes, keys) {
const output = [];
var [ entries, isKeyValue ] = previewEntries(value);
if (isKeyValue)
entries = zip2(entries);
for (const entry of entries) {
if (ctx.maxArrayLength === output.length) {
output.push('... more items');
break;
}
output.push(formatValue(ctx, entry, recurseTimes));
}
for (var n = 0; n < keys.length; n++) {
output.push(formatProperty(ctx, value, recurseTimes, keys[n], 0));
}
return output;
function formatWeakMap(ctx, value, recurseTimes, keys) {
const entries = previewEntries(value);
return formatMapIterInner(ctx, value, recurseTimes, keys, entries, kWeak);
}

function formatMapIterator(ctx, value, recurseTimes, keys) {
return formatCollectionIterator(ctx, value, recurseTimes, keys);
function formatSetIterator(ctx, value, recurseTimes, keys) {
const entries = previewEntries(value);
return formatSetIterInner(ctx, value, recurseTimes, keys, entries, kIterator);
}

function formatSetIterator(ctx, value, recurseTimes, keys) {
return formatCollectionIterator(ctx, value, recurseTimes, keys);
function formatMapIterator(ctx, value, recurseTimes, keys) {
const [entries, isKeyValue] = previewEntries(value, true);
if (isKeyValue) {
return formatMapIterInner(
ctx, value, recurseTimes, keys, entries, kMapEntries);
}

return formatSetIterInner(ctx, value, recurseTimes, keys, entries, kIterator);
}

function formatPromise(ctx, value, recurseTimes, keys) {
Expand Down
3 changes: 3 additions & 0 deletions src/node_util.cc
View file
Expand Up @@ -57,6 +57,9 @@ static void PreviewEntries(const FunctionCallbackInfo<Value>& args) {
Local<Array> entries;
if (!args[0].As<Object>()->PreviewEntries(&is_key_value).ToLocal(&entries))
return;
// Fast path for WeakMap, WeakSet and Set iterators.
if (args.Length() == 1)
return args.GetReturnValue().Set(entries);
Local<Array> ret = Array::New(env->isolate(), 2);
ret->Set(env->context(), 0, entries).FromJust();
ret->Set(env->context(), 1, v8::Boolean::New(env->isolate(), is_key_value))
Expand Down
49 changes: 26 additions & 23 deletions test/parallel/test-util-inspect.js
View file
Expand Up @@ -447,13 +447,15 @@ assert.strictEqual(util.inspect(-5e-324), '-5e-324');
{
const map = new Map();
map.set(1, 2);
const [ vals ] = previewEntries(map.entries());
const valsOutput = [];
for (const o of vals) {
valsOutput.push(o);
}

assert.strictEqual(util.inspect(valsOutput), '[ 1, 2 ]');
// Passing only a single argument to indicate a set iterator.
const valsSetIterator = previewEntries(map.entries());
// Passing through true to indicate a map iterator.
const valsMapIterEntries = previewEntries(map.entries(), true);
const valsMapIterKeys = previewEntries(map.keys(), true);

assert.strictEqual(util.inspect(valsSetIterator), '[ 1, 2 ]');
assert.strictEqual(util.inspect(valsMapIterEntries), '[ [ 1, 2 ], true ]');
assert.strictEqual(util.inspect(valsMapIterKeys), '[ [ 1 ], false ]');
}

// Test for other constructors in different context.
Expand Down Expand Up @@ -965,18 +967,19 @@ if (typeof Symbol !== 'undefined') {
// Test Map iterators.
{
const map = new Map([['foo', 'bar']]);
assert.strictEqual(util.inspect(map.keys()), "[Map Iterator] { 'foo' }");
assert.strictEqual(util.inspect(map.values()), "[Map Iterator] { 'bar' }");
assert.strictEqual(util.inspect(map.entries()),
"[Map Iterator] { [ 'foo', 'bar' ] }");
assert.strictEqual(util.inspect(map.keys()), '[Map Iterator] { \'foo\' }');
assert.strictEqual(util.inspect(map.values()), '[Map Iterator] { \'bar\' }');
map.set('A', 'B!');
assert.strictEqual(util.inspect(map.entries(), { maxArrayLength: 1 }),
"[Map Iterator] { [ 'foo', 'bar' ], ... 1 more item }");
// Make sure the iterator doesn't get consumed.
const keys = map.keys();
assert.strictEqual(util.inspect(keys), "[Map Iterator] { 'foo' }");
assert.strictEqual(util.inspect(keys), "[Map Iterator] { 'foo' }");
assert.strictEqual(util.inspect(keys), "[Map Iterator] { 'foo', 'A' }");
assert.strictEqual(util.inspect(keys), "[Map Iterator] { 'foo', 'A' }");
keys.extra = true;
assert.strictEqual(
util.inspect(keys, { maxArrayLength: 0 }),
'[Map Iterator] { ... more items, extra: true }');
'[Map Iterator] { ... 2 more items, extra: true }');
}

// Test Set iterators.
Expand All @@ -992,7 +995,7 @@ if (typeof Symbol !== 'undefined') {
keys.extra = true;
assert.strictEqual(
util.inspect(keys, { maxArrayLength: 1 }),
'[Set Iterator] { 1, ... more items, extra: true }');
'[Set Iterator] { 1, ... 1 more item, extra: true }');
}

// Test alignment of items in container.
Expand Down Expand Up @@ -1413,17 +1416,17 @@ util.inspect(process);
assert.strictEqual(out, expect);

out = util.inspect(weakMap, { maxArrayLength: 0, showHidden: true });
expect = 'WeakMap { ... more items }';
expect = 'WeakMap { ... 2 more items }';
assert.strictEqual(out, expect);

weakMap.extra = true;
out = util.inspect(weakMap, { maxArrayLength: 1, showHidden: true });
// It is not possible to determine the output reliable.
expect = 'WeakMap { [ [length]: 0 ] => {}, ... more items, extra: true }';
const expectAlt = 'WeakMap { {} => [ [length]: 0 ], ... more items, ' +
expect = 'WeakMap { [ [length]: 0 ] => {}, ... 1 more item, extra: true }';
const expectAlt = 'WeakMap { {} => [ [length]: 0 ], ... 1 more item, ' +
'extra: true }';
assert(out === expect || out === expectAlt,
`Found "${out}" rather than "${expect}" or "${expectAlt}"`);
`Found: "${out}"\nrather than: "${expect}"\nor: "${expectAlt}"`);
}

{ // Test WeakSet
Expand All @@ -1437,17 +1440,17 @@ util.inspect(process);
assert.strictEqual(out, expect);

out = util.inspect(weakSet, { maxArrayLength: -2, showHidden: true });
expect = 'WeakSet { ... more items }';
expect = 'WeakSet { ... 2 more items }';
assert.strictEqual(out, expect);

weakSet.extra = true;
out = util.inspect(weakSet, { maxArrayLength: 1, showHidden: true });
// It is not possible to determine the output reliable.
expect = 'WeakSet { {}, ... more items, extra: true }';
const expectAlt = 'WeakSet { [ 1, [length]: 1 ], ... more items, ' +
expect = 'WeakSet { {}, ... 1 more item, extra: true }';
const expectAlt = 'WeakSet { [ 1, [length]: 1 ], ... 1 more item, ' +
'extra: true }';
assert(out === expect || out === expectAlt,
`Found "${out}" rather than "${expect}" or "${expectAlt}"`);
`Found: "${out}"\nrather than: "${expect}"\nor: "${expectAlt}"`);
}

{ // Test argument objects.
Expand Down

0 comments on commit b171fa2

Please sign in to comment.