performance.getEntriesByType() - Web API 接口参考 编辑
getEntriesByType()
方法返回给定类型的 PerformanceEntry
列表The list's members (entries) can be created by making performance marks or measures (for example by calling the mark()
method) at explicit points in time.
Syntax
entries = window.performance.getEntriesByType(type);
Arguments
- type
- The type of entry to retrieve such as "
mark
". The valid entry types are listed inPerformanceEntry.entryType
.
Return value
- entries
- A list of
PerformanceEntry
objects that have the specifiedtype
. The items will be in chronological order based on the entries'startTime
. If no objects have the specifiedtype
, or no argument is provided, an empty list is returned.
Example
function usePerformanceEntryMethods() {
log("PerformanceEntry tests ...");
if (performance.mark === undefined) {
log("... performance.mark Not supported");
return;
}
// Create some performance entries via the mark() method
performance.mark("Begin");
doWork(50000);
performance.mark("End");
performance.mark("Begin");
doWork(100000);
performance.mark("End");
doWork(200000);
performance.mark("End");
// Use getEntries() to iterate through the each entry
var p = performance.getEntries();
for (var i=0; i < p.length; i++) {
log("Entry[" + i + "]");
checkPerformanceEntry(p[i]);
}
// Use getEntries(name, entryType) to get specific entries
p = performance.getEntries({name : "Begin", entryType: "mark"});
for (var i=0; i < p.length; i++) {
log("Begin[" + i + "]");
checkPerformanceEntry(p[i]);
}
// Use getEntriesByType() to get all "mark" entries
p = performance.getEntriesByType("mark");
for (var i=0; i < p.length; i++) {
log ("Mark only entry[" + i + "]: name = " + p[i].name +
"; startTime = " + p[i].startTime +
"; duration = " + p[i].duration);
}
// Use getEntriesByName() to get all "mark" entries named "Begin"
p = performance.getEntriesByName("Begin", "mark");
for (var i=0; i < p.length; i++) {
log ("Mark and Begin entry[" + i + "]: name = " + p[i].name +
"; startTime = " + p[i].startTime +
"; duration = " + p[i].duration);
}
}
Specifications
Specification | Status | Comment |
---|---|---|
Performance Timeline Level 2 getEntriesByType() | Candidate Recommendation | |
Performance Timeline getEntriesByType() | Recommendation | Initial definition. |
Browser compatibility
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