<!--
Copyright 2020 The Chromium Authors
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->

<!--
This file is used to generate a comprehensive list of Image histograms
along with a detailed description for each histogram.

For best practices on writing histogram descriptions, see
https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/metrics/histograms/README.md

Please follow the instructions in the OWNERS file in this directory to find a
reviewer. If no OWNERS file exists, please consider signing up at
go/reviewing-metrics (Googlers only), as all subdirectories are expected to
have an OWNERS file. As a last resort you can send the CL to
chromium-metrics-reviews@google.com.
-->

<histogram-configuration>

<histograms>

<variants name="ImageAnnotationServiceAnnotationType">
  <variant name="DescCaption."
      summary="Caption annotations from the description engine"/>
  <variant name="DescLabel."
      summary="Label annotations from the description engine"/>
  <variant name="DescOcr."
      summary="OCR (text extraction) annotations from the description engine"/>
  <variant name="DescUnknown."
      summary="Annotations of an unknown type from the description engine"/>
  <variant name="Ocr."
      summary="OCR (text extraction) annotations from the specialized OCR
               engine"/>
</variants>

<variants name="ImageFetcherCacheStrategy">
  <variant name=".BestEffort" summary="LRU cache strategy."/>
  <variant name=".HoldUntilExpired"
      summary="Hold the cache file until expired."/>
</variants>

<variants name="ImageFetcherClients">
  <variant name=".AnswerSuggestions"
      summary="Showing cache patterns only for AnswerSuggestions."/>
  <variant name=".AssistantDetails"
      summary="Showing cache patterns only for AssistantDetails."/>
  <variant name=".AutofillCardArt"
      summary="Show customized card-art image for credit card suggestions on
               Android."/>
  <variant name=".AutofillImageFetcher"
      summary="Show customized card art image for credit card."/>
  <variant name=".ContextualSuggestions"
      summary="Showing cache patterns only for ContextualSuggestions."/>
  <variant name=".Cryptids" summary="Asset fetcher for cryptid rendering."/>
  <variant name=".EduAccountLoginProfileImageFetcher"
      summary="Profile image fetcher for EDU account login flow"/>
  <variant name=".EntitySuggestions"
      summary="Showing cache patterns only for EntitySuggestions."/>
  <variant name=".FedCMAccountChooser"
      summary="Profile image fetcher for FedCM Account chooser."/>
  <variant name=".Feed" summary="Showing cache patterns only for Feed."/>
  <variant name=".Internal"
      summary="Showing cache patterns only for Internal."/>
  <variant name=".NewTabPageAnimatedLogo"
      summary="Showing cache patterns only for NewTabPageAnimatedLogo."/>
  <variant name=".OfflinePages"
      summary="Showing cache patterns only for OfflinePages."/>
  <variant name=".PriceDropNotification"
      summary="Images fetched for the icon of price drop notification."/>
  <variant name=".QueryTiles" summary="Showing Query tiles images."/>
  <variant name=".SharePreview" summary="Images fetched for Share previews."/>
  <variant name=".VideoTutorialsIPH"
      summary="Showing thumbnails for video tutorials IPH."/>
  <variant name=".VideoTutorialsList"
      summary="Showing thumbnails for video tutorials list view."/>
  <variant name=".WebNotes"
      summary="Images fetched and used to render Web Notes templates."/>
</variants>

<histogram name="Image.ResampleMS" units="?" expires_after="M79">
  <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
  <summary>
    Time it takes to do high-quality image resampling for images that are
    resized. Non-resized images and ones our heuristic decides can be done
    &quot;badly&quot; are not counted.
  </summary>
</histogram>

<histogram name="ImageAnnotationService.AccessibilityV1.CacheHit"
    enum="BooleanCacheHit" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each image processed by the image annotation service, records whether or
    not results for the image already existed in the client-side cache. A hit
    means that image data was not transmitted to the image annotation server.
  </summary>
</histogram>

<histogram name="ImageAnnotationService.AccessibilityV1.ClientResult"
    enum="ImageAnnotationServiceClientResult" expires_after="2022-10-30">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each request made by a client feature to the image annotation service,
    reports the final status of the service response.
  </summary>
</histogram>

<histogram name="ImageAnnotationService.AccessibilityV1.DescType"
    enum="ImageAnnotationServiceDescType" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each annotation backend run by the image annotation server, records the
    gRPC status reported.
  </summary>
</histogram>

<histogram name="ImageAnnotationService.AccessibilityV1.EncodedJpegSizeKB"
    units="KB" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each image sent from a client feature to the image annotation service,
    reports the image's final size (in kilobytes) after resizing and reencoding.
  </summary>
</histogram>

<histogram name="ImageAnnotationService.AccessibilityV1.EngineKnown"
    enum="BooleanKnown" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each annotation backend run by the image annotation server, records
    whether or not the backend is recognised by this version of Chrome.
  </summary>
</histogram>

<histogram
    name="ImageAnnotationService.AccessibilityV1.ImageRequestIncludesDesc"
    enum="BooleanIncluded" expires_after="M105">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each image request sent to the image annotation server, records whether
    or not the description backend is included among the requested backends.

    The description backend will not be included when the image is known to
    violate the description model policy (i.e. be too small or have too-high an
    aspect ratio).
  </summary>
</histogram>

<histogram
    name="ImageAnnotationService.AccessibilityV1.ImageRequestIncludesIcon"
    enum="BooleanIncluded" expires_after="M105">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each image request sent to the image annotation server, records whether
    or not the icon backend is included among the requested backends.

    The icon backend will not be included when the image is known to violate the
    icon model policy (i.e. be too large or have too-high an aspect ratio).
  </summary>
</histogram>

<histogram name="ImageAnnotationService.AccessibilityV1.JsonParseSuccess"
    enum="BooleanSuccess" expires_after="2022-10-31">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each non-empty response sent from the image annotation server, records
    whether or not JSON data were successfully parsed from the response body.
  </summary>
</histogram>

<histogram name="ImageAnnotationService.AccessibilityV1.PixelFetchSuccess"
    enum="BooleanSuccess" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each pixel fetch request sent from the image annotation service to a
    client feature, records whether or not encoded pixel data were successfully
    returned to the service.
  </summary>
</histogram>

<histogram name="ImageAnnotationService.AccessibilityV1.ServerHttpResponseCode"
    enum="HttpResponseCode" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each HTTP response from the image annotation server, reports the
    associated HTTP code.
  </summary>
</histogram>

<histogram name="ImageAnnotationService.AccessibilityV1.ServerLatencyMs"
    units="ms" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each HTTP response from the image annotation server, reports the time
    elapsed (in milliseconds) since the corresponding request was sent.
  </summary>
</histogram>

<histogram name="ImageAnnotationService.AccessibilityV1.ServerNetError"
    enum="NetErrorCodes" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each HTTP request sent to the image annotation server, reports the net
    error (or OK status) of the request.
  </summary>
</histogram>

<histogram name="ImageAnnotationService.AccessibilityV1.ServerRequestSizeKB"
    units="KB" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each HTTP request sent to the image annotation server, reports the size
    of the request. Measured in kilobytes, since a request can contain the pixel
    data of multiple images.
  </summary>
</histogram>

<histogram
    name="ImageAnnotationService.AccessibilityV1.ServerResponseSizeBytes"
    units="bytes" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each HTTP response from the image annotation server, reports the
    response size in bytes.
  </summary>
</histogram>

<histogram name="ImageAnnotationService.AccessibilityV1.SourcePixelCount"
    units="pixels" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each image sent from a client feature to the image annotation service,
    reports the image's original (i.e. pre-scaling) area in pixels. Images with
    pixel count above a certain threshold will be resized prior to transmission.
  </summary>
</histogram>

<histogram
    name="ImageAnnotationService.{ImageAnnotationServiceAnnotationType}AccessibilityV1.Confidence"
    units="%" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each annotation of the given type returned by the image annotation
    server, records the confidence (as a percentage) produced by the ML model
    for the annotation. {ImageAnnotationServiceAnnotationType}
  </summary>
  <token key="ImageAnnotationServiceAnnotationType"
      variants="ImageAnnotationServiceAnnotationType"/>
</histogram>

<histogram
    name="ImageAnnotationService.{ImageAnnotationServiceAnnotationType}AccessibilityV1.Empty"
    enum="BooleanEmpty" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each annotation of the given type returned by the image annotation
    server, records whether or not the text of the annotation was empty. This is
    sometimes valid, e.g. for text extraction (OCR) on an image that does not
    contain any text. {ImageAnnotationServiceAnnotationType}
  </summary>
  <token key="ImageAnnotationServiceAnnotationType"
      variants="ImageAnnotationServiceAnnotationType"/>
</histogram>

<histogram
    name="ImageAnnotationService.{ImageAnnotationServiceAnnotationType}AccessibilityV1.Status"
    enum="GoogleRpcCode" expires_after="2022-04-24">
  <owner>dtseng@chromium.org</owner>
  <owner>amoylan@chromium.org</owner>
  <owner>martis@chromium.org</owner>
  <summary>
    For each annotation backend run by the image annotation server, records the
    gRPC status reported. {ImageAnnotationServiceAnnotationType}
  </summary>
  <token key="ImageAnnotationServiceAnnotationType"
      variants="ImageAnnotationServiceAnnotationType"/>
</histogram>

<histogram name="ImageFetcher.CacheMetadataCount{ImageFetcherCacheStrategy}"
    units="records" expires_after="2023-06-01">
  <owner>fgorski@chromium.org</owner>
  <owner>wylieb@chromium.org</owner>
  <summary>
    The total number of metadata entries in the image fetcher cache metadata
    database for a given cache strategy. Recorded during cache eviction process.
    {ImageFetcherCacheStrategy}
  </summary>
  <token key="ImageFetcherCacheStrategy" variants="ImageFetcherCacheStrategy"/>
</histogram>

<histogram name="ImageFetcher.CacheSize{ImageFetcherCacheStrategy}" units="KB"
    expires_after="2023-06-01">
  <owner>fgorski@chromium.org</owner>
  <owner>wylieb@chromium.org</owner>
  <summary>
    The total size of the cache for a given cache strategy. Recorded during
    cache eviction process. {ImageFetcherCacheStrategy}
  </summary>
  <token key="ImageFetcherCacheStrategy" variants="ImageFetcherCacheStrategy"/>
</histogram>

<histogram name="ImageFetcher.Events{ImageFetcherClients}"
    enum="ImageFetcherEvent" expires_after="2023-06-01">
  <owner>fgorski@chromium.org</owner>
  <owner>wylieb@chromium.org</owner>
  <summary>
    Events that track the lifecycle and performance of the cached_image_fetcher.
    The events reported include: success/failure conditions, various recoverable
    errors and a couple of dead-end errors. {ImageFetcherClients}
  </summary>
  <token key="ImageFetcherClients" variants="ImageFetcherClients">
    <variant name=""/>
  </token>
</histogram>

<histogram name="ImageFetcher.ImageLoadFromCacheTimeJava{ImageFetcherClients}"
    units="ms" expires_after="2023-06-01">
  <owner>fgorski@chromium.org</owner>
  <owner>wylieb@chromium.org</owner>
  <summary>
    The time it takes for cached_image_fetcher to load an image from the cache
    in Java. {ImageFetcherClients}
  </summary>
  <token key="ImageFetcherClients" variants="ImageFetcherClients">
    <variant name=""/>
  </token>
</histogram>

<histogram name="ImageFetcher.ImageLoadFromCacheTime{ImageFetcherClients}"
    units="ms" expires_after="2023-06-01">
  <owner>fgorski@chromium.org</owner>
  <owner>wylieb@chromium.org</owner>
  <summary>
    The time it takes for cached_image_fetcher to load an image from the cache
    in native. {ImageFetcherClients}
  </summary>
  <token key="ImageFetcherClients" variants="ImageFetcherClients">
    <variant name=""/>
  </token>
</histogram>

<histogram name="ImageFetcher.ImageLoadFromNativeTimeJava{ImageFetcherClients}"
    units="ms" expires_after="2023-06-01">
  <owner>fgorski@chromium.org</owner>
  <owner>wylieb@chromium.org</owner>
  <summary>
    The time it takes for cached_image_fetcher to load an image from native
    code. Only recorded on successful loads. {ImageFetcherClients}
  </summary>
  <token key="ImageFetcherClients" variants="ImageFetcherClients">
    <variant name=""/>
  </token>
</histogram>

<histogram
    name="ImageFetcher.ImageLoadFromNetworkAfterCacheHit{ImageFetcherClients}"
    units="ms" expires_after="2023-06-01">
  <owner>fgorski@chromium.org</owner>
  <owner>wylieb@chromium.org</owner>
  <summary>
    The time it takes for cached_image_fetcher to load an image from the network
    after a cache hit. {ImageFetcherClients}
  </summary>
  <token key="ImageFetcherClients" variants="ImageFetcherClients">
    <variant name=""/>
  </token>
</histogram>

<histogram name="ImageFetcher.ImageLoadFromNetworkTime{ImageFetcherClients}"
    units="ms" expires_after="2023-06-01">
  <owner>fgorski@chromium.org</owner>
  <owner>wylieb@chromium.org</owner>
  <summary>
    The time it takes for cached_image_fetcher to load an image from the
    network. {ImageFetcherClients}
  </summary>
  <token key="ImageFetcherClients" variants="ImageFetcherClients">
    <variant name=""/>
  </token>
</histogram>

<histogram name="ImageFetcher.LoadImageMetadata" units="ms"
    expires_after="2023-06-01">
  <owner>fgorski@chromium.org</owner>
  <owner>wylieb@chromium.org</owner>
  <summary>
    The time it takes to load an image's metadata from the metadata store.
  </summary>
</histogram>

<histogram name="ImageFetcher.RequestStatusCode{ImageFetcherClients}"
    enum="CombinedHttpResponseAndNetErrorCode" expires_after="2023-06-01">
  <owner>fgorski@chromium.org</owner>
  <owner>wylieb@chromium.org</owner>
  <summary>
    Android: The integer status code of network requests made by the image data
    fetcher. This code includes both protocol(1xx-5xx) and non-protocol(-xxx)
    errors. Recorded when a request completes. {ImageFetcherClients}
  </summary>
  <token key="ImageFetcherClients" variants="ImageFetcherClients">
    <variant name=""/>
  </token>
</histogram>

<histogram name="ImageFetcher.TimeSinceLastCacheLRUEviction" units="ms"
    expires_after="2023-06-01">
  <owner>fgorski@chromium.org</owner>
  <owner>wylieb@chromium.org</owner>
  <summary>
    The time since the last LRU eviction from the image cache. Recorded when two
    LRU evictions occur within closure proximity to one another. Will be used to
    determine if LRU eviction is happening too frequently.
  </summary>
</histogram>

<histogram name="ImageLoader.Client.Cache.HitMiss" enum="BooleanCacheHit"
    expires_after="2019-01-01">
  <owner>tapted@chromium.org</owner>
  <owner>src/ui/file_manager/OWNERS</owner>
  <summary>
    For each image load request that requested caching, records whether or not
    it was found in the client-side cache. A hit means the request was not
    forwarded to the ImageLoader extension.
  </summary>
</histogram>

<histogram name="ImageLoader.Client.Cache.Usage" units="%"
    expires_after="2019-01-01">
  <owner>tapted@chromium.org</owner>
  <owner>src/ui/file_manager/OWNERS</owner>
  <summary>
    Returns the percentage of the client-side cache that is used for loading
    images, before they are sent to the ImageLoader extension. Expressed as a
    percentage of ImageLoaderClient.CACHE_MEMORY_LIMIT (e.g. 20MB).
  </summary>
</histogram>

<histogram name="ImageLoader.Client.Cached" enum="BooleanRequested"
    expires_after="2019-01-01">
  <owner>tapted@chromium.org</owner>
  <owner>src/ui/file_manager/OWNERS</owner>
  <summary>
    For each image load request records whether or not it requested caching.
  </summary>
</histogram>

</histograms>

</histogram-configuration>