org.nd4j.common.resources.Resolver Maven / Gradle / Ivy
package org.nd4j.common.resources;
import java.io.File;
import java.io.InputStream;
/**
* Resolver interface: used to resolve a path (or directory path) to an actual file.
* This is mainly used to find test resources which need to be downloaded on-demand from a remote location, and
* (if appropriate) cached locally.
*
* @author Alex Black
*/
public interface Resolver {
/**
* Priority of this resolver. 0 is highest priority (check first), larger values are lower priority (check last)
*/
int priority();
/**
* Determine if the specified file resource can be resolved by {@link #asFile(String)} and {@link #asStream(String)}
*
* @param resourcePath Path of the resource to be resolved
* @return True if this resolver is able to resolve the resource file - i.e., whether it is a valid path and exists
*/
boolean exists(String resourcePath);
/**
* Determine if the specified directory resource can be resolved by {@link #copyDirectory(String, File)}
*
* @param dirPath Path of the directory resource to be resolved
* @return True if this resolver is able to resolve the directory - i.e., whether it is a valid path and exists
*/
boolean directoryExists(String dirPath);
/**
* Get the specified resources as a standard local file.
* Note that the resource must exist as determined by {@link #exists(String)}
*
* @param resourcePath Path of the resource.
* @return The local file version of the resource
*/
File asFile(String resourcePath);
/**
* Get the specified resources as an input stream.
* Note that the resource must exist as determined by {@link #exists(String)}
*
* @param resourcePath Path of the resource.
* @return The resource as an input stream
*/
InputStream asStream(String resourcePath);
/**
* Copy the directory resource (recursively) to the specified destination directory
*
* @param dirPath Path of the resource directory to resolve
* @param destinationDir Where the files should be copied to
*/
void copyDirectory(String dirPath, File destinationDir);
/**
* @return True if the resolver has a local cache directory, as returned by {@link #localCacheRoot()}
*/
boolean hasLocalCache();
/**
* @return Root directory of the local cache, or null if {@link #hasLocalCache()} returns false
*/
File localCacheRoot();
/**
* Normalize the path that may be a resource reference.
* For example: "someDir/myFile.zip.resource_reference" --> "someDir/myFile.zip"
* Returns null if the file cannot be resolved.
* If the file is not a reference, the original path is returned
*/
String normalizePath(String path);
}