Collect asset loading metrics

Monitor asset loading at runtime.

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最后更新于 24 天前

Use the

AsyncReadManagerMetrics

class to monitor runtime asset loading and file reading performance. This class records data for all file read operations managed by the

AsyncReadManager

Unity uses the

AsyncReadManager

to read most files at runtime, including AssetBundles, Addressables, and Resources. You can also load files from scripts using

AsyncReadManager.Read

You can use the

AsyncReadManagerMetrics

to do the following:

Start and stop metrics collection.
Retrieve and analyze recorded metrics data.
Filter and summarize data to help your analysis.

This information can help you identify problems with asset loading and measure the impact of your changes have on performance.

Development build requirement

The

AsyncReadManagerMetrics

class is only available in development builds. To ensure compatibility, wrap calls to

AsyncReadManagerMetrics

APIs in an

#if

preprocessor directive using the

ENABLE_PROFILER

symbol. For older Unity versions, use the

UNITY_2020_2_OR_NEWER

symbol to remove the metric code. For example:


#if ENABLE_PROFILER && UNITY_2020_2_OR_NEWER    AsyncReadManagerMetrics.StartCollectingMetrics();#endif

Enable metric collection

Enable metrics collection before any data is recorded. You can do this in one of the following ways:

Call

AsyncReadManagerMetrics.StartCollectingMetrics

in your script.

Pass the
```
-enable-file-read-metrics
```
command-line argument when launching your application.

To collect metrics in Play mode, pass the

-enable-file-read-metrics

argument when launching the Unity Editor. However, the Editor loads some categories of assets, such as textures, and doesn't reload them when you enter Play mode. For complete file I/O metrics, you must collect data from a development build of your application.

Getting metric data

Use

GetMetrics

to retrieve collected metrics from

AsyncReadManagerMetrics

. Specify

AsyncReadManagerMetrics.Flags

to determine whether to clear metrics after retrieval. Clearing metrics removes completed (including canceled and failed) reads but retains queued or in-progress operations. To access the metrics for unfinished operations, call

GetMetrics

again after they complete. By clearing the metrics regularly, you can avoid rereading the same data and also reduce the data overhead of the system.


#if ENABLE_PROFILER && UNITY_2020_2_OR_NEWER    AsyncReadManagerRequestMetric[] metrics         = AsyncReadManagerMetrics.GetMetrics(AsyncReadManagerMetrics.Flags.ClearOnRead);#endif

Metrics data includes the following context data:

The
```
AssetLoadingSubsystem
```
that initiated the read. If unavailable, defaults to
```
Other
```
.
```
AssetName
```
. If unavailable, defaults to empty.
```
AssetTypeID
```
. If unavailable, defaults to zero.

The following is a list of supported asset TypeIDs:

TypeID	Type name
28	Texture2D
117	Texture3D
89	CubeMap
43	Mesh

For other TypeIDs that might appear, refer to YAML class ID reference.

Get summarized data

Get a summary of the

AsyncReadManager

metrics with the following methods:

```
GetCurrentSummaryMetrics
```
: Returns a summary of all the metrics collected after the last time you cleared the metric store.
```
GetSummaryOfMetrics
```
: Returns a summary of the metrics in an array of
```
AsyncReadManagerRequestMetric
```
, which you can get by calling
```
GetMetrics
```
.

For example:


#if ENABLE_PROFILER && UNITY_2020_2_OR_NEWER    AsyncReadManagerSummaryMetrics summaryOfMetrics         = AsyncReadManagerMetrics.GetCurrentSummaryMetrics(AsyncReadManagerMetrics.Flags.ClearOnRead);#endif

Or:


#if ENABLE_PROFILER && UNITY_2020_2_OR_NEWER    AsyncReadManagerRequestMetric[] metrics         = AsyncReadManagerMetrics.GetMetrics(AsyncReadManagerMetrics.Flags.ClearOnRead);    AsyncReadManagerSummaryMetrics summaryOfMetrics         = AsyncReadManagerMetrics.GetSummaryOfMetrics(metrics);#endif

Summary statistics include:

Average bandwidth
Average read size
Asset type with the longest load time
Number of reads
Number of requests
Total bytes read

For a full list of summary metrics, refer to

AsyncReadManagerSummaryMetrics

By default, the summarized statistics include all read operations, including those that are queued or in-progress. You can use a filter to limit the summary to those operations you're interested in. For example, you can use a filter to limit the summarized statistics to completed read operations for texture assets.

注意

Calculating summaries requires processing resources. To avoid affecting your measurements, collect metrics first and summarize them after operations are complete.

Using summary filters

Use

AsyncReadManagerMetricsFilters

to filter summarized data. You can filter by the following:

Asset type: By YAML ID.
Processing state: For example, queued, reading, or completed.
Read type: For example, async or sync.
Priority: For example, high or low.
Subsystem: By
```
AssetLoadingSubsystem
```
.

You can set multiple categories for the same filter. A read operation must match all categories for the metrics of that operation to be included in the summary. For example, you can specify values for both the

ProcessingState

and the

Subsystem

of a filter to summarize only operations in the designated processing states initiated by the designated subsytems.

You can also specify multiple values for a category. In this case, a read operation can match any value you specify for a category for its metrics to be included in the summary. For example, filtering by both mesh and texture includes operations for both asset types.

Additional resources

Asset Loading Profiler module

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