gitiles-servlet/src/main/java/com/google/gitiles/GitilesView.java - gitiles - Rivoreo Source Code Repositories

 // Copyright 2012 Google Inc. All Rights Reserved.
 //
 // 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 com.google.gitiles;

 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 import static com.google.gitiles.GitilesUrls.NAME_ESCAPER;
 import static com.google.gitiles.RevisionParser.PATH_SPLITTER;

 import com.google.common.base.Charsets;
 import com.google.common.base.Objects;
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.LinkedListMultimap;
 import com.google.common.collect.ListMultimap;
 import com.google.common.collect.Multimaps;

 import org.eclipse.jgit.revwalk.RevObject;

 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
 import java.util.List;
 import java.util.Map;

 import javax.servlet.http.HttpServletRequest;

 /**
  * Information about a view in Gitiles.
  * <p>
  * Views are uniquely identified by a type, and dispatched to servlet types by
  * {@link GitilesServlet}. This class contains the list of all types, as
  * well as some methods containing basic information parsed from the URL.
  * Construction happens in {@link ViewFilter}.
  */
 public class GitilesView {
   /** All the possible view types supported in the application. */
   public static enum Type {
     HOST_INDEX,
     REPOSITORY_INDEX,
     REFS,
     REVISION,
     PATH,
     DIFF,
     LOG;
   }

   /** Builder for views. */
   public static class Builder {
     private final Type type;
     private final ListMultimap<String, String> params = LinkedListMultimap.create();

     private String hostName;
     private String servletPath;
     private String repositoryName;
     private Revision revision = Revision.NULL;
     private Revision oldRevision = Revision.NULL;
     private String path;
     private String anchor;

     private Builder(Type type) {
       this.type = type;
     }

     public Builder copyFrom(GitilesView other) {
       hostName = other.hostName;
       servletPath = other.servletPath;
       switch (type) {
         case LOG:
         case DIFF:
           oldRevision = other.oldRevision;
           // Fallthrough.
         case PATH:
           path = other.path;
           // Fallthrough.
         case REVISION:
           revision = other.revision;
           // Fallthrough.
         case REFS:
         case REPOSITORY_INDEX:
           repositoryName = other.repositoryName;
           // Fallthrough.
         default:
           break;
       }
       // Don't copy params.
       return this;
     }

     public Builder copyFrom(HttpServletRequest req) {
       return copyFrom(ViewFilter.getView(req));
     }

     public Builder setHostName(String hostName) {
       this.hostName = checkNotNull(hostName);
       return this;
     }

     public String getHostName() {
       return hostName;
     }

     public Builder setServletPath(String servletPath) {
       this.servletPath = checkNotNull(servletPath);
       return this;
     }

     public String getServletPath() {
       return servletPath;
     }

     public Builder setRepositoryName(String repositoryName) {
       switch (type) {
         case HOST_INDEX:
           throw new IllegalStateException(String.format(
               "cannot set repository name on %s view", type));
         default:
           this.repositoryName = checkNotNull(repositoryName);
           return this;
       }
     }

     public String getRepositoryName() {
       return repositoryName;
     }

     public Builder setRevision(Revision revision) {
       switch (type) {
         case HOST_INDEX:
         case REPOSITORY_INDEX:
         case REFS:
           throw new IllegalStateException(String.format("cannot set revision on %s view", type));
         default:
           this.revision = checkNotNull(revision);
           return this;
       }
     }

     public Builder setRevision(String name) {
       return setRevision(Revision.named(name));
     }

     public Builder setRevision(RevObject obj) {
       return setRevision(Revision.peeled(obj.name(), obj));
     }

     public Builder setRevision(String name, RevObject obj) {
       return setRevision(Revision.peeled(name, obj));
     }

     public Revision getRevision() {
       return revision;
     }

     public Builder setOldRevision(Revision revision) {
       switch (type) {
         case DIFF:
         case LOG:
           this.oldRevision = checkNotNull(revision);
           return this;
         default:
           throw new IllegalStateException(
               String.format("cannot set old revision on %s view", type));
       }
     }

     public Builder setOldRevision(RevObject obj) {
       return setOldRevision(Revision.peeled(obj.name(), obj));
     }

     public Builder setOldRevision(String name, RevObject obj) {
       return setOldRevision(Revision.peeled(name, obj));
     }

     public Revision getOldRevision() {
       return revision;
     }

     public Builder setTreePath(String path) {
       switch (type) {
         case PATH:
         case DIFF:
           this.path = maybeTrimLeadingAndTrailingSlash(checkNotNull(path));
           return this;
         case LOG:
           this.path = path != null ? maybeTrimLeadingAndTrailingSlash(path) : null;
           return this;
         default:
           throw new IllegalStateException(String.format("cannot set path on %s view", type));
       }
     }

     public String getTreePath() {
       return path;
     }

     public Builder putParam(String key, String value) {
       params.put(key, value);
       return this;
     }

     public Builder replaceParam(String key, String value) {
       params.replaceValues(key, ImmutableList.of(value));
       return this;
     }

     public Builder putAllParams(Map<String, String[]> params) {
       for (Map.Entry<String, String[]> e : params.entrySet()) {
         for (String v : e.getValue()) {
           this.params.put(e.getKey(), v);
         }
       }
       return this;
     }

     public ListMultimap<String, String> getParams() {
       return params;
     }

     public Builder setAnchor(String anchor) {
       this.anchor = anchor;
       return this;
     }

     public String getAnchor() {
       return anchor;
     }

     public GitilesView build() {
       switch (type) {
         case HOST_INDEX:
           checkHostIndex();
           break;
         case REPOSITORY_INDEX:
           checkRepositoryIndex();
           break;
         case REFS:
           checkRefs();
           break;
         case REVISION:
           checkRevision();
           break;
         case PATH:
           checkPath();
           break;
         case DIFF:
           checkDiff();
           break;
         case LOG:
           checkLog();
           break;
       }
       return new GitilesView(type, hostName, servletPath, repositoryName, revision,
           oldRevision, path, params, anchor);
     }

     public String toUrl() {
       return build().toUrl();
     }

     private void checkHostIndex() {
       checkState(hostName != null, "missing hostName on %s view", type);
       checkState(servletPath != null, "missing hostName on %s view", type);
     }

     private void checkRepositoryIndex() {
       checkState(repositoryName != null, "missing repository name on %s view", type);
       checkHostIndex();
     }

     private void checkRefs() {
       checkRepositoryIndex();
     }

     private void checkRevision() {
       checkState(revision != Revision.NULL, "missing revision on %s view", type);
       checkRepositoryIndex();
     }

     private void checkDiff() {
       checkPath();
     }

     private void checkLog() {
       checkRevision();
     }

     private void checkPath() {
       checkState(path != null, "missing path on %s view", type);
       checkRevision();
     }
   }

   public static Builder hostIndex() {
     return new Builder(Type.HOST_INDEX);
   }

   public static Builder repositoryIndex() {
     return new Builder(Type.REPOSITORY_INDEX);
   }

   public static Builder refs() {
     return new Builder(Type.REFS);
   }

   public static Builder revision() {
     return new Builder(Type.REVISION);
   }

   public static Builder path() {
     return new Builder(Type.PATH);
   }

   public static Builder diff() {
     return new Builder(Type.DIFF);
   }

   public static Builder log() {
     return new Builder(Type.LOG);
   }

   private static String maybeTrimLeadingAndTrailingSlash(String str) {
     if (str.startsWith("/")) {
       str = str.substring(1);
     }
     return !str.isEmpty() && str.endsWith("/") ? str.substring(0, str.length() - 1) : str;
   }

   private final Type type;
   private final String hostName;
   private final String servletPath;
   private final String repositoryName;
   private final Revision revision;
   private final Revision oldRevision;
   private final String path;
   private final ListMultimap<String, String> params;
   private final String anchor;

   private GitilesView(Type type,
       String hostName,
       String servletPath,
       String repositoryName,
       Revision revision,
       Revision oldRevision,
       String path,
       ListMultimap<String, String> params,
       String anchor) {
     this.type = type;
     this.hostName = hostName;
     this.servletPath = servletPath;
     this.repositoryName = repositoryName;
     this.revision = Objects.firstNonNull(revision, Revision.NULL);
     this.oldRevision = Objects.firstNonNull(oldRevision, Revision.NULL);
     this.path = path;
     this.params = Multimaps.unmodifiableListMultimap(params);
     this.anchor = anchor;
   }

   public String getHostName() {
     return hostName;
   }

   public String getServletPath() {
     return servletPath;
   }

   public String getRepositoryName() {
     return repositoryName;
   }

   public Revision getRevision() {
     return revision;
   }

   public Revision getOldRevision() {
     return oldRevision;
   }

   public String getRevisionRange() {
     if (oldRevision == Revision.NULL) {
       switch (type) {
         case LOG:
         case DIFF:
           // For types that require two revisions, NULL indicates the empty
           // tree/commit.
           return revision.getName() + "^!";
         default:
           // For everything else NULL indicates it is not a range, just a single
           // revision.
           return null;
       }
     } else if (type == Type.DIFF && isFirstParent(revision, oldRevision)) {
       return revision.getName() + "^!";
     } else {
       return oldRevision.getName() + ".." + revision.getName();
     }
   }

   public String getTreePath() {
     return path;
   }

   public ListMultimap<String, String> getParameters() {
     return params;
   }

   public String getAnchor() {
     return anchor;
   }

   public Type getType() {
     return type;
   }

   /** @return an escaped, relative URL representing this view. */
   public String toUrl() {
     StringBuilder url = new StringBuilder(servletPath).append('/');
     ListMultimap<String, String> params = this.params;
     switch (type) {
       case HOST_INDEX:
         params = LinkedListMultimap.create();
         if (!this.params.containsKey("format")) {
           params.put("format", FormatType.HTML.toString());
         }
         params.putAll(this.params);
         break;
       case REPOSITORY_INDEX:
         url.append(repositoryName).append('/');
         break;
       case REFS:
         url.append(repositoryName).append("/+refs");
         break;
       case REVISION:
         url.append(repositoryName).append("/+/").append(revision.getName());
         break;
       case PATH:
         url.append(repositoryName).append("/+/").append(revision.getName()).append('/')
             .append(path);
         break;
       case DIFF:
         url.append(repositoryName).append("/+/");
         if (isFirstParent(revision, oldRevision)) {
           url.append(revision.getName()).append("^!");
         } else {
           url.append(oldRevision.getName()).append("..").append(revision.getName());
         }
         url.append('/').append(path);
         break;
       case LOG:
         url.append(repositoryName).append("/+log/");
         if (oldRevision != Revision.NULL) {
           url.append(oldRevision.getName()).append("..");
         }
         url.append(revision.getName());
         if (path != null) {
           url.append('/').append(path);
         }
         break;
       default:
         throw new IllegalStateException("Unknown view type: " + type);
     }
     String baseUrl = NAME_ESCAPER.apply(url.toString());
     url = new StringBuilder();
     if (!params.isEmpty()) {
       url.append('?').append(paramsToString(params));
     }
     if (!Strings.isNullOrEmpty(anchor)) {
       url.append('#').append(NAME_ESCAPER.apply(anchor));
     }
     return baseUrl + url.toString();
   }

   /**
    * @return a list of maps with "text" and "url" keys for all file paths
    *     leading up to the path represented by this view. All URLs allow
    *     auto-diving into one-entry subtrees; see also
    *     {@link #getBreadcrumbs(List<Boolean>)}.
    */
   public List<Map<String, String>> getBreadcrumbs() {
     return getBreadcrumbs(null);
   }

   /**
    * @param hasSingleTree list of booleans, one per path entry in this view's
    *     path excluding the leaf. True entries indicate the tree at that path
    *     only has a single entry that is another tree.
    * @return a list of maps with "text" and "url" keys for all file paths
    *     leading up to the path represented by this view. URLs whose
    *     corresponding entry in {@code hasSingleTree} is true will disable
    *     auto-diving into one-entry subtrees.
    */
   public List<Map<String, String>> getBreadcrumbs(List<Boolean> hasSingleTree) {
     checkArgument(hasSingleTree == null || type == Type.PATH,
         "hasSingleTree must be null for %s view", type);
     String path = this.path;
     ImmutableList.Builder<Map<String, String>> breadcrumbs = ImmutableList.builder();
     breadcrumbs.add(breadcrumb(hostName, hostIndex().copyFrom(this)));
     if (repositoryName != null) {
       breadcrumbs.add(breadcrumb(repositoryName, repositoryIndex().copyFrom(this)));
     }
     if (type == Type.DIFF) {
       // TODO(dborowitz): Tweak the breadcrumbs template to allow us to render
       // separate links in "old..new".
       breadcrumbs.add(breadcrumb(getRevisionRange(), diff().copyFrom(this).setTreePath("")));
     } else if (type == Type.LOG) {
       // TODO(dborowitz): Add something in the navigation area (probably not
       // a breadcrumb) to allow switching between /+log/ and /+/.
       if (oldRevision == Revision.NULL) {
         breadcrumbs.add(breadcrumb(revision.getName(), log().copyFrom(this).setTreePath(null)));
       } else {
         breadcrumbs.add(breadcrumb(getRevisionRange(), log().copyFrom(this).setTreePath(null)));
       }
       path = Strings.emptyToNull(path);
     } else if (revision != Revision.NULL) {
       breadcrumbs.add(breadcrumb(revision.getName(), revision().copyFrom(this)));
     }
     if (path != null) {
       if (type != Type.LOG) { // The "." breadcrumb would be no different for LOG.
         breadcrumbs.add(breadcrumb(".", copyWithPath().setTreePath("")));
       }
       StringBuilder cur = new StringBuilder();
       List<String> parts = ImmutableList.copyOf(PATH_SPLITTER.omitEmptyStrings().split(path));
       checkArgument(hasSingleTree == null || hasSingleTree.size() == parts.size() - 1,
           "hasSingleTree has wrong number of entries");
       for (int i = 0; i < parts.size(); i++) {
         String part = parts.get(i);
         cur.append(part).append('/');
         String curPath = cur.toString();
         Builder builder = copyWithPath().setTreePath(curPath);
         if (hasSingleTree != null && i < parts.size() - 1 && hasSingleTree.get(i)) {
           builder.replaceParam(PathServlet.AUTODIVE_PARAM, PathServlet.NO_AUTODIVE_VALUE);
         }
         breadcrumbs.add(breadcrumb(part, builder));
       }
     }
     return breadcrumbs.build();
   }

   private static Map<String, String> breadcrumb(String text, Builder url) {
     return ImmutableMap.of("text", text, "url", url.toUrl());
   }

   private Builder copyWithPath() {
     Builder copy;
     switch (type) {
       case DIFF:
         copy = diff();
         break;
       case LOG:
         copy = log();
         break;
       default:
         copy = path();
         break;
     }
     return copy.copyFrom(this);
   }

   private static boolean isFirstParent(Revision rev1, Revision rev2) {
     return rev2 == Revision.NULL
         || rev2.getName().equals(rev1.getName() + "^")
         || rev2.getName().equals(rev1.getName() + "~1");
   }

   private static String paramsToString(ListMultimap<String, String> params) {
     try {
     StringBuilder sb = new StringBuilder();
     boolean first = true;
     for (Map.Entry<String, String> e : params.entries()) {
       if (!first) {
         sb.append('&');
       } else {
         first = false;
       }
       sb.append(URLEncoder.encode(e.getKey(), Charsets.UTF_8.name()));
       if (!"".equals(e.getValue())) {
         sb.append('=')
             .append(URLEncoder.encode(e.getValue(), Charsets.UTF_8.name()));
       }
     }
     return sb.toString();
     } catch (UnsupportedEncodingException e) {
       throw new IllegalStateException(e);
     }
   }
 }
	// Copyright 2012 Google Inc. All Rights Reserved.
	//
	// 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 com.google.gitiles;

	import static com.google.common.base.Preconditions.checkArgument;
	import static com.google.common.base.Preconditions.checkNotNull;
	import static com.google.common.base.Preconditions.checkState;
	import static com.google.gitiles.GitilesUrls.NAME_ESCAPER;
	import static com.google.gitiles.RevisionParser.PATH_SPLITTER;

	import com.google.common.base.Charsets;
	import com.google.common.base.Objects;
	import com.google.common.base.Strings;
	import com.google.common.collect.ImmutableList;
	import com.google.common.collect.ImmutableMap;
	import com.google.common.collect.LinkedListMultimap;
	import com.google.common.collect.ListMultimap;
	import com.google.common.collect.Multimaps;

	import org.eclipse.jgit.revwalk.RevObject;

	import java.io.UnsupportedEncodingException;
	import java.net.URLEncoder;
	import java.util.List;
	import java.util.Map;

	import javax.servlet.http.HttpServletRequest;

	/**
	* Information about a view in Gitiles.
	* <p>
	* Views are uniquely identified by a type, and dispatched to servlet types by
	* {@link GitilesServlet}. This class contains the list of all types, as
	* well as some methods containing basic information parsed from the URL.
	* Construction happens in {@link ViewFilter}.
	*/
	public class GitilesView {
	/** All the possible view types supported in the application. */
	public static enum Type {
	HOST_INDEX,
	REPOSITORY_INDEX,
	REFS,
	REVISION,
	PATH,
	DIFF,
	LOG;
	}

	/** Builder for views. */
	public static class Builder {
	private final Type type;
	private final ListMultimap<String, String> params = LinkedListMultimap.create();

	private String hostName;
	private String servletPath;
	private String repositoryName;
	private Revision revision = Revision.NULL;
	private Revision oldRevision = Revision.NULL;
	private String path;
	private String anchor;

	private Builder(Type type) {
	this.type = type;
	}

	public Builder copyFrom(GitilesView other) {
	hostName = other.hostName;
	servletPath = other.servletPath;
	switch (type) {
	case LOG:
	case DIFF:
	oldRevision = other.oldRevision;
	// Fallthrough.
	case PATH:
	path = other.path;
	// Fallthrough.
	case REVISION:
	revision = other.revision;
	// Fallthrough.
	case REFS:
	case REPOSITORY_INDEX:
	repositoryName = other.repositoryName;
	// Fallthrough.
	default:
	break;
	}
	// Don't copy params.
	return this;
	}

	public Builder copyFrom(HttpServletRequest req) {
	return copyFrom(ViewFilter.getView(req));
	}

	public Builder setHostName(String hostName) {
	this.hostName = checkNotNull(hostName);
	return this;
	}

	public String getHostName() {
	return hostName;
	}

	public Builder setServletPath(String servletPath) {
	this.servletPath = checkNotNull(servletPath);
	return this;
	}

	public String getServletPath() {
	return servletPath;
	}

	public Builder setRepositoryName(String repositoryName) {
	switch (type) {
	case HOST_INDEX:
	throw new IllegalStateException(String.format(
	"cannot set repository name on %s view", type));
	default:
	this.repositoryName = checkNotNull(repositoryName);
	return this;
	}
	}

	public String getRepositoryName() {
	return repositoryName;
	}

	public Builder setRevision(Revision revision) {
	switch (type) {
	case HOST_INDEX:
	case REPOSITORY_INDEX:
	case REFS:
	throw new IllegalStateException(String.format("cannot set revision on %s view", type));
	default:
	this.revision = checkNotNull(revision);
	return this;
	}
	}

	public Builder setRevision(String name) {
	return setRevision(Revision.named(name));
	}

	public Builder setRevision(RevObject obj) {
	return setRevision(Revision.peeled(obj.name(), obj));
	}

	public Builder setRevision(String name, RevObject obj) {
	return setRevision(Revision.peeled(name, obj));
	}

	public Revision getRevision() {
	return revision;
	}

	public Builder setOldRevision(Revision revision) {
	switch (type) {
	case DIFF:
	case LOG:
	this.oldRevision = checkNotNull(revision);
	return this;
	default:
	throw new IllegalStateException(
	String.format("cannot set old revision on %s view", type));
	}
	}

	public Builder setOldRevision(RevObject obj) {
	return setOldRevision(Revision.peeled(obj.name(), obj));
	}

	public Builder setOldRevision(String name, RevObject obj) {
	return setOldRevision(Revision.peeled(name, obj));
	}

	public Revision getOldRevision() {
	return revision;
	}

	public Builder setTreePath(String path) {
	switch (type) {
	case PATH:
	case DIFF:
	this.path = maybeTrimLeadingAndTrailingSlash(checkNotNull(path));
	return this;
	case LOG:
	this.path = path != null ? maybeTrimLeadingAndTrailingSlash(path) : null;
	return this;
	default:
	throw new IllegalStateException(String.format("cannot set path on %s view", type));
	}
	}

	public String getTreePath() {
	return path;
	}

	public Builder putParam(String key, String value) {
	params.put(key, value);
	return this;
	}

	public Builder replaceParam(String key, String value) {
	params.replaceValues(key, ImmutableList.of(value));
	return this;
	}

	public Builder putAllParams(Map<String, String[]> params) {
	for (Map.Entry<String, String[]> e : params.entrySet()) {
	for (String v : e.getValue()) {
	this.params.put(e.getKey(), v);
	}
	}
	return this;
	}

	public ListMultimap<String, String> getParams() {
	return params;
	}

	public Builder setAnchor(String anchor) {
	this.anchor = anchor;
	return this;
	}

	public String getAnchor() {
	return anchor;
	}

	public GitilesView build() {
	switch (type) {
	case HOST_INDEX:
	checkHostIndex();
	break;
	case REPOSITORY_INDEX:
	checkRepositoryIndex();
	break;
	case REFS:
	checkRefs();
	break;
	case REVISION:
	checkRevision();
	break;
	case PATH:
	checkPath();
	break;
	case DIFF:
	checkDiff();
	break;
	case LOG:
	checkLog();
	break;
	}
	return new GitilesView(type, hostName, servletPath, repositoryName, revision,
	oldRevision, path, params, anchor);
	}

	public String toUrl() {
	return build().toUrl();
	}

	private void checkHostIndex() {
	checkState(hostName != null, "missing hostName on %s view", type);
	checkState(servletPath != null, "missing hostName on %s view", type);
	}

	private void checkRepositoryIndex() {
	checkState(repositoryName != null, "missing repository name on %s view", type);
	checkHostIndex();
	}

	private void checkRefs() {
	checkRepositoryIndex();
	}

	private void checkRevision() {
	checkState(revision != Revision.NULL, "missing revision on %s view", type);
	checkRepositoryIndex();
	}

	private void checkDiff() {
	checkPath();
	}

	private void checkLog() {
	checkRevision();
	}

	private void checkPath() {
	checkState(path != null, "missing path on %s view", type);
	checkRevision();
	}
	}

	public static Builder hostIndex() {
	return new Builder(Type.HOST_INDEX);
	}

	public static Builder repositoryIndex() {
	return new Builder(Type.REPOSITORY_INDEX);
	}

	public static Builder refs() {
	return new Builder(Type.REFS);
	}

	public static Builder revision() {
	return new Builder(Type.REVISION);
	}

	public static Builder path() {
	return new Builder(Type.PATH);
	}

	public static Builder diff() {
	return new Builder(Type.DIFF);
	}

	public static Builder log() {
	return new Builder(Type.LOG);
	}

	private static String maybeTrimLeadingAndTrailingSlash(String str) {
	if (str.startsWith("/")) {
	str = str.substring(1);
	}
	return !str.isEmpty() && str.endsWith("/") ? str.substring(0, str.length() - 1) : str;
	}

	private final Type type;
	private final String hostName;
	private final String servletPath;
	private final String repositoryName;
	private final Revision revision;
	private final Revision oldRevision;
	private final String path;
	private final ListMultimap<String, String> params;
	private final String anchor;

	private GitilesView(Type type,
	String hostName,
	String servletPath,
	String repositoryName,
	Revision revision,
	Revision oldRevision,
	String path,
	ListMultimap<String, String> params,
	String anchor) {
	this.type = type;
	this.hostName = hostName;
	this.servletPath = servletPath;
	this.repositoryName = repositoryName;
	this.revision = Objects.firstNonNull(revision, Revision.NULL);
	this.oldRevision = Objects.firstNonNull(oldRevision, Revision.NULL);
	this.path = path;
	this.params = Multimaps.unmodifiableListMultimap(params);
	this.anchor = anchor;
	}

	public String getHostName() {
	return hostName;
	}

	public String getServletPath() {
	return servletPath;
	}

	public String getRepositoryName() {
	return repositoryName;
	}

	public Revision getRevision() {
	return revision;
	}

	public Revision getOldRevision() {
	return oldRevision;
	}

	public String getRevisionRange() {
	if (oldRevision == Revision.NULL) {
	switch (type) {
	case LOG:
	case DIFF:
	// For types that require two revisions, NULL indicates the empty
	// tree/commit.
	return revision.getName() + "^!";
	default:
	// For everything else NULL indicates it is not a range, just a single
	// revision.
	return null;
	}
	} else if (type == Type.DIFF && isFirstParent(revision, oldRevision)) {
	return revision.getName() + "^!";
	} else {
	return oldRevision.getName() + ".." + revision.getName();
	}
	}

	public String getTreePath() {
	return path;
	}

	public ListMultimap<String, String> getParameters() {
	return params;
	}

	public String getAnchor() {
	return anchor;
	}

	public Type getType() {
	return type;
	}

	/** @return an escaped, relative URL representing this view. */
	public String toUrl() {
	StringBuilder url = new StringBuilder(servletPath).append('/');
	ListMultimap<String, String> params = this.params;
	switch (type) {
	case HOST_INDEX:
	params = LinkedListMultimap.create();
	if (!this.params.containsKey("format")) {
	params.put("format", FormatType.HTML.toString());
	}
	params.putAll(this.params);
	break;
	case REPOSITORY_INDEX:
	url.append(repositoryName).append('/');
	break;
	case REFS:
	url.append(repositoryName).append("/+refs");
	break;
	case REVISION:
	url.append(repositoryName).append("/+/").append(revision.getName());
	break;
	case PATH:
	url.append(repositoryName).append("/+/").append(revision.getName()).append('/')
	.append(path);
	break;
	case DIFF:
	url.append(repositoryName).append("/+/");
	if (isFirstParent(revision, oldRevision)) {
	url.append(revision.getName()).append("^!");
	} else {
	url.append(oldRevision.getName()).append("..").append(revision.getName());
	}
	url.append('/').append(path);
	break;
	case LOG:
	url.append(repositoryName).append("/+log/");
	if (oldRevision != Revision.NULL) {
	url.append(oldRevision.getName()).append("..");
	}
	url.append(revision.getName());
	if (path != null) {
	url.append('/').append(path);
	}
	break;
	default:
	throw new IllegalStateException("Unknown view type: " + type);
	}
	String baseUrl = NAME_ESCAPER.apply(url.toString());
	url = new StringBuilder();
	if (!params.isEmpty()) {
	url.append('?').append(paramsToString(params));
	}
	if (!Strings.isNullOrEmpty(anchor)) {
	url.append('#').append(NAME_ESCAPER.apply(anchor));
	}
	return baseUrl + url.toString();
	}

	/**
	* @return a list of maps with "text" and "url" keys for all file paths
	* leading up to the path represented by this view. All URLs allow
	* auto-diving into one-entry subtrees; see also
	* {@link #getBreadcrumbs(List<Boolean>)}.
	*/
	public List<Map<String, String>> getBreadcrumbs() {
	return getBreadcrumbs(null);
	}

	/**
	* @param hasSingleTree list of booleans, one per path entry in this view's
	* path excluding the leaf. True entries indicate the tree at that path
	* only has a single entry that is another tree.
	* @return a list of maps with "text" and "url" keys for all file paths
	* leading up to the path represented by this view. URLs whose
	* corresponding entry in {@code hasSingleTree} is true will disable
	* auto-diving into one-entry subtrees.
	*/
	public List<Map<String, String>> getBreadcrumbs(List<Boolean> hasSingleTree) {
	checkArgument(hasSingleTree == null \|\| type == Type.PATH,
	"hasSingleTree must be null for %s view", type);
	String path = this.path;
	ImmutableList.Builder<Map<String, String>> breadcrumbs = ImmutableList.builder();
	breadcrumbs.add(breadcrumb(hostName, hostIndex().copyFrom(this)));
	if (repositoryName != null) {
	breadcrumbs.add(breadcrumb(repositoryName, repositoryIndex().copyFrom(this)));
	}
	if (type == Type.DIFF) {
	// TODO(dborowitz): Tweak the breadcrumbs template to allow us to render
	// separate links in "old..new".
	breadcrumbs.add(breadcrumb(getRevisionRange(), diff().copyFrom(this).setTreePath("")));
	} else if (type == Type.LOG) {
	// TODO(dborowitz): Add something in the navigation area (probably not
	// a breadcrumb) to allow switching between /+log/ and /+/.
	if (oldRevision == Revision.NULL) {
	breadcrumbs.add(breadcrumb(revision.getName(), log().copyFrom(this).setTreePath(null)));
	} else {
	breadcrumbs.add(breadcrumb(getRevisionRange(), log().copyFrom(this).setTreePath(null)));
	}
	path = Strings.emptyToNull(path);
	} else if (revision != Revision.NULL) {
	breadcrumbs.add(breadcrumb(revision.getName(), revision().copyFrom(this)));
	}
	if (path != null) {
	if (type != Type.LOG) { // The "." breadcrumb would be no different for LOG.
	breadcrumbs.add(breadcrumb(".", copyWithPath().setTreePath("")));
	}
	StringBuilder cur = new StringBuilder();
	List<String> parts = ImmutableList.copyOf(PATH_SPLITTER.omitEmptyStrings().split(path));
	checkArgument(hasSingleTree == null \|\| hasSingleTree.size() == parts.size() - 1,
	"hasSingleTree has wrong number of entries");
	for (int i = 0; i < parts.size(); i++) {
	String part = parts.get(i);
	cur.append(part).append('/');
	String curPath = cur.toString();
	Builder builder = copyWithPath().setTreePath(curPath);
	if (hasSingleTree != null && i < parts.size() - 1 && hasSingleTree.get(i)) {
	builder.replaceParam(PathServlet.AUTODIVE_PARAM, PathServlet.NO_AUTODIVE_VALUE);
	}
	breadcrumbs.add(breadcrumb(part, builder));
	}
	}
	return breadcrumbs.build();
	}

	private static Map<String, String> breadcrumb(String text, Builder url) {
	return ImmutableMap.of("text", text, "url", url.toUrl());
	}

	private Builder copyWithPath() {
	Builder copy;
	switch (type) {
	case DIFF:
	copy = diff();
	break;
	case LOG:
	copy = log();
	break;
	default:
	copy = path();
	break;
	}
	return copy.copyFrom(this);
	}

	private static boolean isFirstParent(Revision rev1, Revision rev2) {
	return rev2 == Revision.NULL
	\|\| rev2.getName().equals(rev1.getName() + "^")
	\|\| rev2.getName().equals(rev1.getName() + "~1");
	}

	private static String paramsToString(ListMultimap<String, String> params) {
	try {
	StringBuilder sb = new StringBuilder();
	boolean first = true;
	for (Map.Entry<String, String> e : params.entries()) {
	if (!first) {
	sb.append('&');
	} else {
	first = false;
	}
	sb.append(URLEncoder.encode(e.getKey(), Charsets.UTF_8.name()));
	if (!"".equals(e.getValue())) {
	sb.append('=')
	.append(URLEncoder.encode(e.getValue(), Charsets.UTF_8.name()));
	}
	}
	return sb.toString();
	} catch (UnsupportedEncodingException e) {
	throw new IllegalStateException(e);
	}
	}
	}