IFileDownloader

public interface IFileDownloader

com.android.tradefed.build.IFileDownloader

Known indirect subclasses

FileDownloadCacheWrapper, GCSFileDownloader

FileDownloadCacheWrapper	A wrapper class that provides `FileDownloadCache` facilities while implementing the `IFileDownloader` interface.
GCSFileDownloader	File downloader to download file from google cloud storage (GCS).

Interface for downloading a remote file.

Summary

Public methods
`default void`	`acquireDownloadPermit()` If concurrency limit is supported, take a download permit.
`default void`	`downloadFile(String remoteFilePath, File destFile, long startOffset, long size)` Alternate form of `downloadFile(String, File)`, that allows caller to download a section of the file and save to a specific destination file.
`abstract void`	`downloadFile(String relativeRemotePath, File destFile)` Alternate form of `downloadFile(String)`, that allows caller to specify the destination file the remote contents should be placed in.
`abstract File`	`downloadFile(String remoteFilePath)` Downloads a remote file to a temporary file on local disk.
`default void`	`downloadZippedFiles(File destDir, String remoteFilePath, includeFilters, excludeFilters)` Download the files matching given filters in a remote zip file.
`default boolean`	`isFresh(File localFile, String remoteFilePath)` Check local file's freshness.
`default void`	`releaseDownloadPermit()` If concurrency limit is supported, release a download permit.

Public methods

acquireDownloadPermit

public void acquireDownloadPermit ()

If concurrency limit is supported, take a download permit.

downloadFile

public void downloadFile (String remoteFilePath, 
                File destFile, 
                long startOffset, 
                long size)

Alternate form of downloadFile(String, File), that allows caller to download a section of the file and save to a specific destination file.

Parameters
`remoteFilePath`	`String`: the remote path to the file to download, relative to an implementation-specific root.
`destFile`	`File`: the file to place the downloaded contents into. Should not exist.
`startOffset`	`long`: the start offset in the remote file.
`size`	`long`: the number of bytes to download from the remote file. Set it to a negative value to download the whole file.

Throws
`BuildRetrievalError`	if file could not be downloaded

downloadFile

public abstract void downloadFile (String relativeRemotePath, 
                File destFile)

Alternate form of downloadFile(String), that allows caller to specify the destination file the remote contents should be placed in.

Parameters
`relativeRemotePath`	`String`: the remote path to the file to download, relative to an implementation-specific root.
`destFile`	`File`: the file to place the downloaded contents into. Should not exist.

Throws
`BuildRetrievalError`	if file could not be downloaded

downloadFile

public abstract File downloadFile (String remoteFilePath)

Downloads a remote file to a temporary file on local disk.

Parameters
`remoteFilePath`	`String`: the remote path to the file to download, relative to a implementation specific root.

Returns
`File`	the temporary local downloaded `ERROR(/File)`.

Throws
`BuildRetrievalError`	if file could not be downloaded

downloadZippedFiles

public void downloadZippedFiles (File destDir, 
                String remoteFilePath, 
                 includeFilters, 
                 excludeFilters)

Download the files matching given filters in a remote zip file.

A file inside the remote zip file is only downloaded to its path matches any of the include filters but not the exclude filters.

Parameters
`destDir`	`File`: the file to place the downloaded contents into.
`remoteFilePath`	`String`: the remote path to the file to download, relative to an implementation specific root.
`includeFilters`	: a list of filters to download matching files.
`excludeFilters`	: a list of filters to skip downloading matching files.

Throws
`BuildRetrievalError`	if files could not be downloaded.

isFresh

public boolean isFresh (File localFile, 
                String remoteFilePath)

Check local file's freshness. If local file is the same as remote file, then it's fresh. If not, local file is stale. This is mainly used for cache. The default implementation will always return true, so if the file is immutable it will never need to check freshness.

Parameters
`localFile`	`File`: local file.
`remoteFilePath`	`String`: remote file path.

Returns
`boolean`	True if local file is fresh, otherwise false.

Throws
`BuildRetrievalError`

releaseDownloadPermit

public void releaseDownloadPermit ()

If concurrency limit is supported, release a download permit.