/*
* Copyright 2013 Cloudera Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.kitesdk.data;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.collect.Maps;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Map;
import org.kitesdk.data.spi.Constraints;
import org.kitesdk.data.spi.Conversions;
import org.kitesdk.data.spi.Pair;
import org.kitesdk.data.spi.Registration;
import org.kitesdk.data.spi.URIPattern;
/**
* Builds dataset and view URIs
*
* @since 0.17.0
*/
public class URIBuilder {
public static final String DATASET_NAME_OPTION = "dataset";
public static final String NAMESPACE_OPTION = "namespace";
public static final String NAMESPACE_DEFAULT = "default";
public static final String DATASET_SCHEME = "dataset";
public static final String VIEW_SCHEME = "view";
public static final String REPO_SCHEME = "repo";
/**
* Builds a dataset URI from the given repository URI string, namespace, and
* dataset name.
*
* @param repoUri a repository URI string
* @param namespace a String namespace
* @param dataset a String dataset name
* @return a dataset URI for the namespace and dataset name in the repository
*
* @since 0.17.0
*/
public static URI build(String repoUri, String namespace, String dataset) {
return build(URI.create(repoUri), namespace, dataset);
}
/**
* Builds a dataset URI from the given repository URI, namespace, and dataset
* name.
*
* @param repoUri a repository URI
* @param namespace a String namespace
* @param dataset a String dataset name
* @return a dataset URI for the namespace and dataset name in the repository
*
* @since 0.17.0
*/
public static URI build(URI repoUri, String namespace, String dataset) {
return new URIBuilder(repoUri, namespace, dataset).build();
}
private URIPattern pattern;
private boolean isView = false;
// LinkedHashMap preserves the order so that constructed URIs are more predictable
private Map<String, String> options = Maps.newLinkedHashMap();
/**
* Constructs a builder based on the given repository URI and
* {@link Dataset#getName() dataset name}.
*
* @param repoUri the repository URI
* @param namespace A namespace, or logical group name, for the dataset.
* @param datasetName the {@link Dataset} name
*
* @since 0.17.0
*/
public URIBuilder(String repoUri, String namespace, String datasetName) {
this(URI.create(repoUri), namespace, datasetName);
}
/**
* Constructs a builder based on the given repository URI and
* {@link Dataset#getName() dataset name}.
*
* @param repoUri the repository URI
* @param namespace A namespace, or logical group name, for the dataset.
* @param dataset the {@link Dataset} name
*
* @since 0.17.0
*/
public URIBuilder(URI repoUri, String namespace, String dataset) {
Preconditions.checkNotNull(repoUri, "Repository URI cannot be null");
Preconditions.checkNotNull(dataset, "Dataset name cannot be null");
Preconditions.checkArgument(REPO_SCHEME.equals(repoUri.getScheme()),
"Repository URI must start with \"repo:\" but was:" + repoUri);
Pair<URIPattern, Map<String, String>> pair = Registration
.lookupPatternByRepoUri(URI.create(repoUri.getRawSchemeSpecificPart()));
this.pattern = pair.first();
options.putAll(pair.second());
options.put(DATASET_NAME_OPTION, dataset);
options.put(NAMESPACE_OPTION, namespace);
}
/**
* Constructs a builder based on the given dataset or view URI string.
*
* @param uri a dataset or view URI String
*/
public URIBuilder(String uri) {
this(URI.create(uri));
}
/**
* Constructs a builder based on the given dataset or view URI.
*
* @param uri a dataset or view URI
*
* @since 0.17.0
*/
public URIBuilder(URI uri) {
Preconditions.checkNotNull(uri, "URI cannot be null");
boolean isViewUri = VIEW_SCHEME.equals(uri.getScheme());
Preconditions.checkArgument(isViewUri ||
DATASET_SCHEME.equals(uri.getScheme()),
"Not a dataset or view URI: " + uri);
Pair<URIPattern, Map<String, String>> pair = Registration
.lookupDatasetPattern(URI.create(uri.getRawSchemeSpecificPart()));
this.pattern = pair.first();
this.isView = isViewUri;
options.put(NAMESPACE_OPTION, NAMESPACE_DEFAULT);
options.putAll(pair.second());
}
/**
* Adds a set of constraints.
*
* @param constraints a set of constraints
* @return this builder for method chaining
*/
@VisibleForTesting
URIBuilder constraints(Constraints constraints) {
options.putAll(constraints.toQueryMap());
this.isView = !constraints.isUnbounded();
return this;
}
/**
* Adds a view constraint equivalent to
* {@link org.kitesdk.data.RefinableView#with(String, Object...)}
*
* @param name the field name of the Entity
* @param value the field value
* @return this builder for method chaining
*
* @since 0.17.0
*/
public URIBuilder with(String name, Object value) {
options.put(name, Conversions.makeString(value));
this.isView = true;
return this;
}
/**
* Sets the namespace that is used to construct the dataset URI.
*
* @param namespace a String namespace
* @return this builder for method chaining
*
* @since 0.17.0
*/
public URIBuilder namespace(String namespace) {
options.put(NAMESPACE_OPTION, namespace);
return this;
}
/**
* Sets the dataset name that is used to construct the dataset URI.
*
* @param dataset a String dataset name
* @return this builder for method chaining
*
* @since 0.17.0
*/
public URIBuilder dataset(String dataset) {
options.put(DATASET_NAME_OPTION, dataset);
return this;
}
/**
* Returns a dataset or view URI encompassing the given constraints. The
* referenced {@link Dataset} or {@link View} may be loaded again with
* {@link Datasets#load(URI, Class)}.
*
* @return a dataset or view URI
*
* @since 0.17.0
*/
public URI build() {
try {
return new URI((isView ? VIEW_SCHEME : DATASET_SCHEME) + ":" +
pattern.construct(options).toString());
} catch (URISyntaxException e) {
throw new IllegalArgumentException("Could not build URI", e);
}
}
}