Add third_party/google-input-tools: Take 2

third_party/google_input_tools/third_party/closure_library/closure/goog/uri/utils.js

Index: third_party/google_input_tools/third_party/closure_library/closure/goog/uri/utils.js
diff --git a/third_party/google_input_tools/third_party/closure_library/closure/goog/uri/utils.js b/third_party/google_input_tools/third_party/closure_library/closure/goog/uri/utils.js
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+// Copyright 2008 The Closure Library Authors. 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.
+
+/**
+ * @fileoverview Simple utilities for dealing with URI strings.
+ *
+ * This is intended to be a lightweight alternative to constructing goog.Uri
+ * objects.  Whereas goog.Uri adds several kilobytes to the binary regardless
+ * of how much of its functionality you use, this is designed to be a set of
+ * mostly-independent utilities so that the compiler includes only what is
+ * necessary for the task.  Estimated savings of porting is 5k pre-gzip and
+ * 1.5k post-gzip.  To ensure the savings remain, future developers should
+ * avoid adding new functionality to existing functions, but instead create
+ * new ones and factor out shared code.
+ *
+ * Many of these utilities have limited functionality, tailored to common
+ * cases.  The query parameter utilities assume that the parameter keys are
+ * already encoded, since most keys are compile-time alphanumeric strings.  The
+ * query parameter mutation utilities also do not tolerate fragment identifiers.
+ *
+ * By design, these functions can be slower than goog.Uri equivalents.
+ * Repeated calls to some of functions may be quadratic in behavior for IE,
+ * although the effect is somewhat limited given the 2kb limit.
+ *
+ * One advantage of the limited functionality here is that this approach is
+ * less sensitive to differences in URI encodings than goog.Uri, since these
+ * functions modify the strings in place, rather than decoding and
+ * re-encoding.
+ *
+ * Uses features of RFC 3986 for parsing/formatting URIs:
+ *   http://www.ietf.org/rfc/rfc3986.txt
+ *
+ * @author gboyer@google.com (Garrett Boyer) - The "lightened" design.
+ * @author msamuel@google.com (Mike Samuel) - Domain knowledge and regexes.
+ */
+
+goog.provide('goog.uri.utils');
+goog.provide('goog.uri.utils.ComponentIndex');
+goog.provide('goog.uri.utils.QueryArray');
+goog.provide('goog.uri.utils.QueryValue');
+goog.provide('goog.uri.utils.StandardQueryParam');
+
+goog.require('goog.asserts');
+goog.require('goog.string');
+goog.require('goog.userAgent');
+
+
+/**
+ * Character codes inlined to avoid object allocations due to charCode.
+ * @enum {number}
+ * @private
+ */
+goog.uri.utils.CharCode_ = {
+  AMPERSAND: 38,
+  EQUAL: 61,
+  HASH: 35,
+  QUESTION: 63
+};
+
+
+/**
+ * Builds a URI string from already-encoded parts.
+ *
+ * No encoding is performed.  Any component may be omitted as either null or
+ * undefined.
+ *
+ * @param {?string=} opt_scheme The scheme such as 'http'.
+ * @param {?string=} opt_userInfo The user name before the '@'.
+ * @param {?string=} opt_domain The domain such as 'www.google.com', already
+ *     URI-encoded.
+ * @param {(string|number|null)=} opt_port The port number.
+ * @param {?string=} opt_path The path, already URI-encoded.  If it is not
+ *     empty, it must begin with a slash.
+ * @param {?string=} opt_queryData The URI-encoded query data.
+ * @param {?string=} opt_fragment The URI-encoded fragment identifier.
+ * @return {string} The fully combined URI.
+ */
+goog.uri.utils.buildFromEncodedParts = function(opt_scheme, opt_userInfo,
+    opt_domain, opt_port, opt_path, opt_queryData, opt_fragment) {
+  var out = '';
+
+  if (opt_scheme) {
+    out += opt_scheme + ':';
+  }
+
+  if (opt_domain) {
+    out += '//';
+
+    if (opt_userInfo) {
+      out += opt_userInfo + '@';
+    }
+
+    out += opt_domain;
+
+    if (opt_port) {
+      out += ':' + opt_port;
+    }
+  }
+
+  if (opt_path) {
+    out += opt_path;
+  }
+
+  if (opt_queryData) {
+    out += '?' + opt_queryData;
+  }
+
+  if (opt_fragment) {
+    out += '#' + opt_fragment;
+  }
+
+  return out;
+};
+
+
+/**
+ * A regular expression for breaking a URI into its component parts.
+ *
+ * {@link http://www.ietf.org/rfc/rfc3986.txt} says in Appendix B
+ * As the "first-match-wins" algorithm is identical to the "greedy"
+ * disambiguation method used by POSIX regular expressions, it is natural and
+ * commonplace to use a regular expression for parsing the potential five
+ * components of a URI reference.
+ *
+ * The following line is the regular expression for breaking-down a
+ * well-formed URI reference into its components.
+ *
+ * <pre>
+ * ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
+ *  12            3  4          5       6  7        8 9
+ * </pre>
+ *
+ * The numbers in the second line above are only to assist readability; they
+ * indicate the reference points for each subexpression (i.e., each paired
+ * parenthesis). We refer to the value matched for subexpression <n> as $<n>.
+ * For example, matching the above expression to
+ * <pre>
+ *     http://www.ics.uci.edu/pub/ietf/uri/#Related
+ * </pre>
+ * results in the following subexpression matches:
+ * <pre>
+ *    $1 = http:
+ *    $2 = http
+ *    $3 = //www.ics.uci.edu
+ *    $4 = www.ics.uci.edu
+ *    $5 = /pub/ietf/uri/
+ *    $6 = <undefined>
+ *    $7 = <undefined>
+ *    $8 = #Related
+ *    $9 = Related
+ * </pre>
+ * where <undefined> indicates that the component is not present, as is the
+ * case for the query component in the above example. Therefore, we can
+ * determine the value of the five components as
+ * <pre>
+ *    scheme    = $2
+ *    authority = $4
+ *    path      = $5
+ *    query     = $7
+ *    fragment  = $9
+ * </pre>
+ *
+ * The regular expression has been modified slightly to expose the
+ * userInfo, domain, and port separately from the authority.
+ * The modified version yields
+ * <pre>
+ *    $1 = http              scheme
+ *    $2 = <undefined>       userInfo -\
+ *    $3 = www.ics.uci.edu   domain     | authority
+ *    $4 = <undefined>       port     -/
+ *    $5 = /pub/ietf/uri/    path
+ *    $6 = <undefined>       query without ?
+ *    $7 = Related           fragment without #
+ * </pre>
+ * @type {!RegExp}
+ * @private
+ */
+goog.uri.utils.splitRe_ = new RegExp(
+    '^' +
+    '(?:' +
+        '([^:/?#.]+)' +                  // scheme - ignore special characters
+                                         // used by other URL parts such as :,
+                                         // ?, /, #, and .
+    ':)?' +
+    '(?://' +
+        '(?:([^/?#]*)@)?' +              // userInfo
+        '([^/#?]*?)' +                   // domain
+        '(?::([0-9]+))?' +               // port
+        '(?=[/#?]|$)' +                  // authority-terminating character
+    ')?' +
+    '([^?#]+)?' +                        // path
+    '(?:\\?([^#]*))?' +                  // query
+    '(?:#(.*))?' +                       // fragment
+    '$');
+
+
+/**
+ * The index of each URI component in the return value of goog.uri.utils.split.
+ * @enum {number}
+ */
+goog.uri.utils.ComponentIndex = {
+  SCHEME: 1,
+  USER_INFO: 2,
+  DOMAIN: 3,
+  PORT: 4,
+  PATH: 5,
+  QUERY_DATA: 6,
+  FRAGMENT: 7
+};
+
+
+/**
+ * Splits a URI into its component parts.
+ *
+ * Each component can be accessed via the component indices; for example:
+ * <pre>
+ * goog.uri.utils.split(someStr)[goog.uri.utils.CompontentIndex.QUERY_DATA];
+ * </pre>
+ *
+ * @param {string} uri The URI string to examine.
+ * @return {!Array.<string|undefined>} Each component still URI-encoded.
+ *     Each component that is present will contain the encoded value, whereas
+ *     components that are not present will be undefined or empty, depending
+ *     on the browser's regular expression implementation.  Never null, since
+ *     arbitrary strings may still look like path names.
+ */
+goog.uri.utils.split = function(uri) {
+  goog.uri.utils.phishingProtection_();
+
+  // See @return comment -- never null.
+  return /** @type {!Array.<string|undefined>} */ (
+      uri.match(goog.uri.utils.splitRe_));
+};
+
+
+/**
+ * Safari has a nasty bug where if you have an http URL with a username, e.g.,
+ * http://evil.com%2F@google.com/
+ * Safari will report that window.location.href is
+ * http://evil.com/google.com/
+ * so that anyone who tries to parse the domain of that URL will get
+ * the wrong domain. We've seen exploits where people use this to trick
+ * Safari into loading resources from evil domains.
+ *
+ * To work around this, we run a little "Safari phishing check", and throw
+ * an exception if we see this happening.
+ *
+ * There is no convenient place to put this check. We apply it to
+ * anyone doing URI parsing on Webkit. We're not happy about this, but
+ * it fixes the problem.
+ *
+ * This should be removed once Safari fixes their bug.
+ *
+ * Exploit reported by Masato Kinugawa.
+ *
+ * @type {boolean}
+ * @private
+ */
+goog.uri.utils.needsPhishingProtection_ = goog.userAgent.WEBKIT;
+
+
+/**
+ * Check to see if the user is being phished.
+ * @private
+ */
+goog.uri.utils.phishingProtection_ = function() {
+  if (goog.uri.utils.needsPhishingProtection_) {
+    // Turn protection off, so that we don't recurse.
+    goog.uri.utils.needsPhishingProtection_ = false;
+
+    // Use quoted access, just in case the user isn't using location externs.
+    var location = goog.global['location'];
+    if (location) {
+      var href = location['href'];
+      if (href) {
+        var domain = goog.uri.utils.getDomain(href);
+        if (domain && domain != location['hostname']) {
+          // Phishing attack
+          goog.uri.utils.needsPhishingProtection_ = true;
+          throw Error();
+        }
+      }
+    }
+  }
+};
+
+
+/**
+ * @param {?string} uri A possibly null string.
+ * @return {?string} The string URI-decoded, or null if uri is null.
+ * @private
+ */
+goog.uri.utils.decodeIfPossible_ = function(uri) {
+  return uri && decodeURIComponent(uri);
+};
+
+
+/**
+ * Gets a URI component by index.
+ *
+ * It is preferred to use the getPathEncoded() variety of functions ahead,
+ * since they are more readable.
+ *
+ * @param {goog.uri.utils.ComponentIndex} componentIndex The component index.
+ * @param {string} uri The URI to examine.
+ * @return {?string} The still-encoded component, or null if the component
+ *     is not present.
+ * @private
+ */
+goog.uri.utils.getComponentByIndex_ = function(componentIndex, uri) {
+  // Convert undefined, null, and empty string into null.
+  return goog.uri.utils.split(uri)[componentIndex] || null;
+};
+
+
+/**
+ * @param {string} uri The URI to examine.
+ * @return {?string} The protocol or scheme, or null if none.  Does not
+ *     include trailing colons or slashes.
+ */
+goog.uri.utils.getScheme = function(uri) {
+  return goog.uri.utils.getComponentByIndex_(
+      goog.uri.utils.ComponentIndex.SCHEME, uri);
+};
+
+
+/**
+ * Gets the effective scheme for the URL.  If the URL is relative then the
+ * scheme is derived from the page's location.
+ * @param {string} uri The URI to examine.
+ * @return {string} The protocol or scheme, always lower case.
+ */
+goog.uri.utils.getEffectiveScheme = function(uri) {
+  var scheme = goog.uri.utils.getScheme(uri);
+  if (!scheme && self.location) {
+    var protocol = self.location.protocol;
+    scheme = protocol.substr(0, protocol.length - 1);
+  }
+  // NOTE: When called from a web worker in Firefox 3.5, location maybe null.
+  // All other browsers with web workers support self.location from the worker.
+  return scheme ? scheme.toLowerCase() : '';
+};
+
+
+/**
+ * @param {string} uri The URI to examine.
+ * @return {?string} The user name still encoded, or null if none.
+ */
+goog.uri.utils.getUserInfoEncoded = function(uri) {
+  return goog.uri.utils.getComponentByIndex_(
+      goog.uri.utils.ComponentIndex.USER_INFO, uri);
+};
+
+
+/**
+ * @param {string} uri The URI to examine.
+ * @return {?string} The decoded user info, or null if none.
+ */
+goog.uri.utils.getUserInfo = function(uri) {
+  return goog.uri.utils.decodeIfPossible_(
+      goog.uri.utils.getUserInfoEncoded(uri));
+};
+
+
+/**
+ * @param {string} uri The URI to examine.
+ * @return {?string} The domain name still encoded, or null if none.
+ */
+goog.uri.utils.getDomainEncoded = function(uri) {
+  return goog.uri.utils.getComponentByIndex_(
+      goog.uri.utils.ComponentIndex.DOMAIN, uri);
+};
+
+
+/**
+ * @param {string} uri The URI to examine.
+ * @return {?string} The decoded domain, or null if none.
+ */
+goog.uri.utils.getDomain = function(uri) {
+  return goog.uri.utils.decodeIfPossible_(goog.uri.utils.getDomainEncoded(uri));
+};
+
+
+/**
+ * @param {string} uri The URI to examine.
+ * @return {?number} The port number, or null if none.
+ */
+goog.uri.utils.getPort = function(uri) {
+  // Coerce to a number.  If the result of getComponentByIndex_ is null or
+  // non-numeric, the number coersion yields NaN.  This will then return
+  // null for all non-numeric cases (though also zero, which isn't a relevant
+  // port number).
+  return Number(goog.uri.utils.getComponentByIndex_(
+      goog.uri.utils.ComponentIndex.PORT, uri)) || null;
+};
+
+
+/**
+ * @param {string} uri The URI to examine.
+ * @return {?string} The path still encoded, or null if none. Includes the
+ *     leading slash, if any.
+ */
+goog.uri.utils.getPathEncoded = function(uri) {
+  return goog.uri.utils.getComponentByIndex_(
+      goog.uri.utils.ComponentIndex.PATH, uri);
+};
+
+
+/**
+ * @param {string} uri The URI to examine.
+ * @return {?string} The decoded path, or null if none.  Includes the leading
+ *     slash, if any.
+ */
+goog.uri.utils.getPath = function(uri) {
+  return goog.uri.utils.decodeIfPossible_(goog.uri.utils.getPathEncoded(uri));
+};
+
+
+/**
+ * @param {string} uri The URI to examine.
+ * @return {?string} The query data still encoded, or null if none.  Does not
+ *     include the question mark itself.
+ */
+goog.uri.utils.getQueryData = function(uri) {
+  return goog.uri.utils.getComponentByIndex_(
+      goog.uri.utils.ComponentIndex.QUERY_DATA, uri);
+};
+
+
+/**
+ * @param {string} uri The URI to examine.
+ * @return {?string} The fragment identifier, or null if none.  Does not
+ *     include the hash mark itself.
+ */
+goog.uri.utils.getFragmentEncoded = function(uri) {
+  // The hash mark may not appear in any other part of the URL.
+  var hashIndex = uri.indexOf('#');
+  return hashIndex < 0 ? null : uri.substr(hashIndex + 1);
+};
+
+
+/**
+ * @param {string} uri The URI to examine.
+ * @param {?string} fragment The encoded fragment identifier, or null if none.
+ *     Does not include the hash mark itself.
+ * @return {string} The URI with the fragment set.
+ */
+goog.uri.utils.setFragmentEncoded = function(uri, fragment) {
+  return goog.uri.utils.removeFragment(uri) + (fragment ? '#' + fragment : '');
+};
+
+
+/**
+ * @param {string} uri The URI to examine.
+ * @return {?string} The decoded fragment identifier, or null if none.  Does
+ *     not include the hash mark.
+ */
+goog.uri.utils.getFragment = function(uri) {
+  return goog.uri.utils.decodeIfPossible_(
+      goog.uri.utils.getFragmentEncoded(uri));
+};
+
+
+/**
+ * Extracts everything up to the port of the URI.
+ * @param {string} uri The URI string.
+ * @return {string} Everything up to and including the port.
+ */
+goog.uri.utils.getHost = function(uri) {
+  var pieces = goog.uri.utils.split(uri);
+  return goog.uri.utils.buildFromEncodedParts(
+      pieces[goog.uri.utils.ComponentIndex.SCHEME],
+      pieces[goog.uri.utils.ComponentIndex.USER_INFO],
+      pieces[goog.uri.utils.ComponentIndex.DOMAIN],
+      pieces[goog.uri.utils.ComponentIndex.PORT]);
+};
+
+
+/**
+ * Extracts the path of the URL and everything after.
+ * @param {string} uri The URI string.
+ * @return {string} The URI, starting at the path and including the query
+ *     parameters and fragment identifier.
+ */
+goog.uri.utils.getPathAndAfter = function(uri) {
+  var pieces = goog.uri.utils.split(uri);
+  return goog.uri.utils.buildFromEncodedParts(null, null, null, null,
+      pieces[goog.uri.utils.ComponentIndex.PATH],
+      pieces[goog.uri.utils.ComponentIndex.QUERY_DATA],
+      pieces[goog.uri.utils.ComponentIndex.FRAGMENT]);
+};
+
+
+/**
+ * Gets the URI with the fragment identifier removed.
+ * @param {string} uri The URI to examine.
+ * @return {string} Everything preceding the hash mark.
+ */
+goog.uri.utils.removeFragment = function(uri) {
+  // The hash mark may not appear in any other part of the URL.
+  var hashIndex = uri.indexOf('#');
+  return hashIndex < 0 ? uri : uri.substr(0, hashIndex);
+};
+
+
+/**
+ * Ensures that two URI's have the exact same domain, scheme, and port.
+ *
+ * Unlike the version in goog.Uri, this checks protocol, and therefore is
+ * suitable for checking against the browser's same-origin policy.
+ *
+ * @param {string} uri1 The first URI.
+ * @param {string} uri2 The second URI.
+ * @return {boolean} Whether they have the same domain and port.
+ */
+goog.uri.utils.haveSameDomain = function(uri1, uri2) {
+  var pieces1 = goog.uri.utils.split(uri1);
+  var pieces2 = goog.uri.utils.split(uri2);
+  return pieces1[goog.uri.utils.ComponentIndex.DOMAIN] ==
+             pieces2[goog.uri.utils.ComponentIndex.DOMAIN] &&
+         pieces1[goog.uri.utils.ComponentIndex.SCHEME] ==
+             pieces2[goog.uri.utils.ComponentIndex.SCHEME] &&
+         pieces1[goog.uri.utils.ComponentIndex.PORT] ==
+             pieces2[goog.uri.utils.ComponentIndex.PORT];
+};
+
+
+/**
+ * Asserts that there are no fragment or query identifiers, only in uncompiled
+ * mode.
+ * @param {string} uri The URI to examine.
+ * @private
+ */
+goog.uri.utils.assertNoFragmentsOrQueries_ = function(uri) {
+  // NOTE: would use goog.asserts here, but jscompiler doesn't know that
+  // indexOf has no side effects.
+  if (goog.DEBUG && (uri.indexOf('#') >= 0 || uri.indexOf('?') >= 0)) {
+    throw Error('goog.uri.utils: Fragment or query identifiers are not ' +
+        'supported: [' + uri + ']');
+  }
+};
+
+
+/**
+ * Supported query parameter values by the parameter serializing utilities.
+ *
+ * If a value is null or undefined, the key-value pair is skipped, as an easy
+ * way to omit parameters conditionally.  Non-array parameters are converted
+ * to a string and URI encoded.  Array values are expanded into multiple
+ * &key=value pairs, with each element stringized and URI-encoded.
+ *
+ * @typedef {*}
+ */
+goog.uri.utils.QueryValue;
+
+
+/**
+ * An array representing a set of query parameters with alternating keys
+ * and values.
+ *
+ * Keys are assumed to be URI encoded already and live at even indices.  See
+ * goog.uri.utils.QueryValue for details on how parameter values are encoded.
+ *
+ * Example:
+ * <pre>
+ * var data = [
+ *   // Simple param: ?name=BobBarker
+ *   'name', 'BobBarker',
+ *   // Conditional param -- may be omitted entirely.
+ *   'specialDietaryNeeds', hasDietaryNeeds() ? getDietaryNeeds() : null,
+ *   // Multi-valued param: &house=LosAngeles&house=NewYork&house=null
+ *   'house', ['LosAngeles', 'NewYork', null]
+ * ];
+ * </pre>
+ *
+ * @typedef {!Array.<string|goog.uri.utils.QueryValue>}
+ */
+goog.uri.utils.QueryArray;
+
+
+/**
+ * Appends a URI and query data in a string buffer with special preconditions.
+ *
+ * Internal implementation utility, performing very few object allocations.
+ *
+ * @param {!Array.<string|undefined>} buffer A string buffer.  The first element
+ *     must be the base URI, and may have a fragment identifier.  If the array
+ *     contains more than one element, the second element must be an ampersand,
+ *     and may be overwritten, depending on the base URI.  Undefined elements
+ *     are treated as empty-string.
+ * @return {string} The concatenated URI and query data.
+ * @private
+ */
+goog.uri.utils.appendQueryData_ = function(buffer) {
+  if (buffer[1]) {
+    // At least one query parameter was added.  We need to check the
+    // punctuation mark, which is currently an ampersand, and also make sure
+    // there aren't any interfering fragment identifiers.
+    var baseUri = /** @type {string} */ (buffer[0]);
+    var hashIndex = baseUri.indexOf('#');
+    if (hashIndex >= 0) {
+      // Move the fragment off the base part of the URI into the end.
+      buffer.push(baseUri.substr(hashIndex));
+      buffer[0] = baseUri = baseUri.substr(0, hashIndex);
+    }
+    var questionIndex = baseUri.indexOf('?');
+    if (questionIndex < 0) {
+      // No question mark, so we need a question mark instead of an ampersand.
+      buffer[1] = '?';
+    } else if (questionIndex == baseUri.length - 1) {
+      // Question mark is the very last character of the existing URI, so don't
+      // append an additional delimiter.
+      buffer[1] = undefined;
+    }
+  }
+
+  return buffer.join('');
+};
+
+
+/**
+ * Appends key=value pairs to an array, supporting multi-valued objects.
+ * @param {string} key The key prefix.
+ * @param {goog.uri.utils.QueryValue} value The value to serialize.
+ * @param {!Array.<string>} pairs The array to which the 'key=value' strings
+ *     should be appended.
+ * @private
+ */
+goog.uri.utils.appendKeyValuePairs_ = function(key, value, pairs) {
+  if (goog.isArray(value)) {
+    // Convince the compiler it's an array.
+    goog.asserts.assertArray(value);
+    for (var j = 0; j < value.length; j++) {
+      // Convert to string explicitly, to short circuit the null and array
+      // logic in this function -- this ensures that null and undefined get
+      // written as literal 'null' and 'undefined', and arrays don't get
+      // expanded out but instead encoded in the default way.
+      goog.uri.utils.appendKeyValuePairs_(key, String(value[j]), pairs);
+    }
+  } else if (value != null) {
+    // Skip a top-level null or undefined entirely.
+    pairs.push('&', key,
+        // Check for empty string. Zero gets encoded into the url as literal
+        // strings.  For empty string, skip the equal sign, to be consistent
+        // with UriBuilder.java.
+        value === '' ? '' : '=',
+        goog.string.urlEncode(value));
+  }
+};
+
+
+/**
+ * Builds a buffer of query data from a sequence of alternating keys and values.
+ *
+ * @param {!Array.<string|undefined>} buffer A string buffer to append to.  The
+ *     first element appended will be an '&', and may be replaced by the caller.
+ * @param {goog.uri.utils.QueryArray|Arguments} keysAndValues An array with
+ *     alternating keys and values -- see the typedef.
+ * @param {number=} opt_startIndex A start offset into the arary, defaults to 0.
+ * @return {!Array.<string|undefined>} The buffer argument.
+ * @private
+ */
+goog.uri.utils.buildQueryDataBuffer_ = function(
+    buffer, keysAndValues, opt_startIndex) {
+  goog.asserts.assert(Math.max(keysAndValues.length - (opt_startIndex || 0),
+      0) % 2 == 0, 'goog.uri.utils: Key/value lists must be even in length.');
+
+  for (var i = opt_startIndex || 0; i < keysAndValues.length; i += 2) {
+    goog.uri.utils.appendKeyValuePairs_(
+        keysAndValues[i], keysAndValues[i + 1], buffer);
+  }
+
+  return buffer;
+};
+
+
+/**
+ * Builds a query data string from a sequence of alternating keys and values.
+ * Currently generates "&key&" for empty args.
+ *
+ * @param {goog.uri.utils.QueryArray} keysAndValues Alternating keys and
+ *     values.  See the typedef.
+ * @param {number=} opt_startIndex A start offset into the arary, defaults to 0.
+ * @return {string} The encoded query string, in the form 'a=1&b=2'.
+ */
+goog.uri.utils.buildQueryData = function(keysAndValues, opt_startIndex) {
+  var buffer = goog.uri.utils.buildQueryDataBuffer_(
+      [], keysAndValues, opt_startIndex);
+  buffer[0] = ''; // Remove the leading ampersand.
+  return buffer.join('');
+};
+
+
+/**
+ * Builds a buffer of query data from a map.
+ *
+ * @param {!Array.<string|undefined>} buffer A string buffer to append to.  The
+ *     first element appended will be an '&', and may be replaced by the caller.
+ * @param {Object.<goog.uri.utils.QueryValue>} map An object where keys are
+ *     URI-encoded parameter keys, and the values conform to the contract
+ *     specified in the goog.uri.utils.QueryValue typedef.
+ * @return {!Array.<string|undefined>} The buffer argument.
+ * @private
+ */
+goog.uri.utils.buildQueryDataBufferFromMap_ = function(buffer, map) {
+  for (var key in map) {
+    goog.uri.utils.appendKeyValuePairs_(key, map[key], buffer);
+  }
+
+  return buffer;
+};
+
+
+/**
+ * Builds a query data string from a map.
+ * Currently generates "&key&" for empty args.
+ *
+ * @param {Object} map An object where keys are URI-encoded parameter keys,
+ *     and the values are arbitrary types or arrays.  Keys with a null value
+ *     are dropped.
+ * @return {string} The encoded query string, in the form 'a=1&b=2'.
+ */
+goog.uri.utils.buildQueryDataFromMap = function(map) {
+  var buffer = goog.uri.utils.buildQueryDataBufferFromMap_([], map);
+  buffer[0] = '';
+  return buffer.join('');
+};
+
+
+/**
+ * Appends URI parameters to an existing URI.
+ *
+ * The variable arguments may contain alternating keys and values.  Keys are
+ * assumed to be already URI encoded.  The values should not be URI-encoded,
+ * and will instead be encoded by this function.
+ * <pre>
+ * appendParams('http://www.foo.com?existing=true',
+ *     'key1', 'value1',
+ *     'key2', 'value?willBeEncoded',
+ *     'key3', ['valueA', 'valueB', 'valueC'],
+ *     'key4', null);
+ * result: 'http://www.foo.com?existing=true&' +
+ *     'key1=value1&' +
+ *     'key2=value%3FwillBeEncoded&' +
+ *     'key3=valueA&key3=valueB&key3=valueC'
+ * </pre>
+ *
+ * A single call to this function will not exhibit quadratic behavior in IE,
+ * whereas multiple repeated calls may, although the effect is limited by
+ * fact that URL's generally can't exceed 2kb.
+ *
+ * @param {string} uri The original URI, which may already have query data.
+ * @param {...(goog.uri.utils.QueryArray|string|goog.uri.utils.QueryValue)} var_args
+ *     An array or argument list conforming to goog.uri.utils.QueryArray.
+ * @return {string} The URI with all query parameters added.
+ */
+goog.uri.utils.appendParams = function(uri, var_args) {
+  return goog.uri.utils.appendQueryData_(
+      arguments.length == 2 ?
+      goog.uri.utils.buildQueryDataBuffer_([uri], arguments[1], 0) :
+      goog.uri.utils.buildQueryDataBuffer_([uri], arguments, 1));
+};
+
+
+/**
+ * Appends query parameters from a map.
+ *
+ * @param {string} uri The original URI, which may already have query data.
+ * @param {Object} map An object where keys are URI-encoded parameter keys,
+ *     and the values are arbitrary types or arrays.  Keys with a null value
+ *     are dropped.
+ * @return {string} The new parameters.
+ */
+goog.uri.utils.appendParamsFromMap = function(uri, map) {
+  return goog.uri.utils.appendQueryData_(
+      goog.uri.utils.buildQueryDataBufferFromMap_([uri], map));
+};
+
+
+/**
+ * Appends a single URI parameter.
+ *
+ * Repeated calls to this can exhibit quadratic behavior in IE6 due to the
+ * way string append works, though it should be limited given the 2kb limit.
+ *
+ * @param {string} uri The original URI, which may already have query data.
+ * @param {string} key The key, which must already be URI encoded.
+ * @param {*=} opt_value The value, which will be stringized and encoded
+ *     (assumed not already to be encoded).  If omitted, undefined, or null, the
+ *     key will be added as a valueless parameter.
+ * @return {string} The URI with the query parameter added.
+ */
+goog.uri.utils.appendParam = function(uri, key, opt_value) {
+  var paramArr = [uri, '&', key];
+  if (goog.isDefAndNotNull(opt_value)) {
+    paramArr.push('=', goog.string.urlEncode(opt_value));
+  }
+  return goog.uri.utils.appendQueryData_(paramArr);
+};
+
+
+/**
+ * Finds the next instance of a query parameter with the specified name.
+ *
+ * Does not instantiate any objects.
+ *
+ * @param {string} uri The URI to search.  May contain a fragment identifier
+ *     if opt_hashIndex is specified.
+ * @param {number} startIndex The index to begin searching for the key at.  A
+ *     match may be found even if this is one character after the ampersand.
+ * @param {string} keyEncoded The URI-encoded key.
+ * @param {number} hashOrEndIndex Index to stop looking at.  If a hash
+ *     mark is present, it should be its index, otherwise it should be the
+ *     length of the string.
+ * @return {number} The position of the first character in the key's name,
+ *     immediately after either a question mark or a dot.
+ * @private
+ */
+goog.uri.utils.findParam_ = function(
+    uri, startIndex, keyEncoded, hashOrEndIndex) {
+  var index = startIndex;
+  var keyLength = keyEncoded.length;
+
+  // Search for the key itself and post-filter for surronuding punctuation,
+  // rather than expensively building a regexp.
+  while ((index = uri.indexOf(keyEncoded, index)) >= 0 &&
+      index < hashOrEndIndex) {
+    var precedingChar = uri.charCodeAt(index - 1);
+    // Ensure that the preceding character is '&' or '?'.
+    if (precedingChar == goog.uri.utils.CharCode_.AMPERSAND ||
+        precedingChar == goog.uri.utils.CharCode_.QUESTION) {
+      // Ensure the following character is '&', '=', '#', or NaN
+      // (end of string).
+      var followingChar = uri.charCodeAt(index + keyLength);
+      if (!followingChar ||
+          followingChar == goog.uri.utils.CharCode_.EQUAL ||
+          followingChar == goog.uri.utils.CharCode_.AMPERSAND ||
+          followingChar == goog.uri.utils.CharCode_.HASH) {
+        return index;
+      }
+    }
+    index += keyLength + 1;
+  }
+
+  return -1;
+};
+
+
+/**
+ * Regular expression for finding a hash mark or end of string.
+ * @type {RegExp}
+ * @private
+ */
+goog.uri.utils.hashOrEndRe_ = /#|$/;
+
+
+/**
+ * Determines if the URI contains a specific key.
+ *
+ * Performs no object instantiations.
+ *
+ * @param {string} uri The URI to process.  May contain a fragment
+ *     identifier.
+ * @param {string} keyEncoded The URI-encoded key.  Case-sensitive.
+ * @return {boolean} Whether the key is present.
+ */
+goog.uri.utils.hasParam = function(uri, keyEncoded) {
+  return goog.uri.utils.findParam_(uri, 0, keyEncoded,
+      uri.search(goog.uri.utils.hashOrEndRe_)) >= 0;
+};
+
+
+/**
+ * Gets the first value of a query parameter.
+ * @param {string} uri The URI to process.  May contain a fragment.
+ * @param {string} keyEncoded The URI-encoded key.  Case-sensitive.
+ * @return {?string} The first value of the parameter (URI-decoded), or null
+ *     if the parameter is not found.
+ */
+goog.uri.utils.getParamValue = function(uri, keyEncoded) {
+  var hashOrEndIndex = uri.search(goog.uri.utils.hashOrEndRe_);
+  var foundIndex = goog.uri.utils.findParam_(
+      uri, 0, keyEncoded, hashOrEndIndex);
+
+  if (foundIndex < 0) {
+    return null;
+  } else {
+    var endPosition = uri.indexOf('&', foundIndex);
+    if (endPosition < 0 || endPosition > hashOrEndIndex) {
+      endPosition = hashOrEndIndex;
+    }
+    // Progress forth to the end of the "key=" or "key&" substring.
+    foundIndex += keyEncoded.length + 1;
+    // Use substr, because it (unlike substring) will return empty string
+    // if foundIndex > endPosition.
+    return goog.string.urlDecode(
+        uri.substr(foundIndex, endPosition - foundIndex));
+  }
+};
+
+
+/**
+ * Gets all values of a query parameter.
+ * @param {string} uri The URI to process.  May contain a framgnet.
+ * @param {string} keyEncoded The URI-encoded key.  Case-snsitive.
+ * @return {!Array.<string>} All URI-decoded values with the given key.
+ *     If the key is not found, this will have length 0, but never be null.
+ */
+goog.uri.utils.getParamValues = function(uri, keyEncoded) {
+  var hashOrEndIndex = uri.search(goog.uri.utils.hashOrEndRe_);
+  var position = 0;
+  var foundIndex;
+  var result = [];
+
+  while ((foundIndex = goog.uri.utils.findParam_(
+      uri, position, keyEncoded, hashOrEndIndex)) >= 0) {
+    // Find where this parameter ends, either the '&' or the end of the
+    // query parameters.
+    position = uri.indexOf('&', foundIndex);
+    if (position < 0 || position > hashOrEndIndex) {
+      position = hashOrEndIndex;
+    }
+
+    // Progress forth to the end of the "key=" or "key&" substring.
+    foundIndex += keyEncoded.length + 1;
+    // Use substr, because it (unlike substring) will return empty string
+    // if foundIndex > position.
+    result.push(goog.string.urlDecode(uri.substr(
+        foundIndex, position - foundIndex)));
+  }
+
+  return result;
+};
+
+
+/**
+ * Regexp to find trailing question marks and ampersands.
+ * @type {RegExp}
+ * @private
+ */
+goog.uri.utils.trailingQueryPunctuationRe_ = /[?&]($|#)/;
+
+
+/**
+ * Removes all instances of a query parameter.
+ * @param {string} uri The URI to process.  Must not contain a fragment.
+ * @param {string} keyEncoded The URI-encoded key.
+ * @return {string} The URI with all instances of the parameter removed.
+ */
+goog.uri.utils.removeParam = function(uri, keyEncoded) {
+  var hashOrEndIndex = uri.search(goog.uri.utils.hashOrEndRe_);
+  var position = 0;
+  var foundIndex;
+  var buffer = [];
+
+  // Look for a query parameter.
+  while ((foundIndex = goog.uri.utils.findParam_(
+      uri, position, keyEncoded, hashOrEndIndex)) >= 0) {
+    // Get the portion of the query string up to, but not including, the ?
+    // or & starting the parameter.
+    buffer.push(uri.substring(position, foundIndex));
+    // Progress to immediately after the '&'.  If not found, go to the end.
+    // Avoid including the hash mark.
+    position = Math.min((uri.indexOf('&', foundIndex) + 1) || hashOrEndIndex,
+        hashOrEndIndex);
+  }
+
+  // Append everything that is remaining.
+  buffer.push(uri.substr(position));
+
+  // Join the buffer, and remove trailing punctuation that remains.
+  return buffer.join('').replace(
+      goog.uri.utils.trailingQueryPunctuationRe_, '$1');
+};
+
+
+/**
+ * Replaces all existing definitions of a parameter with a single definition.
+ *
+ * Repeated calls to this can exhibit quadratic behavior due to the need to
+ * find existing instances and reconstruct the string, though it should be
+ * limited given the 2kb limit.  Consider using appendParams to append multiple
+ * parameters in bulk.
+ *
+ * @param {string} uri The original URI, which may already have query data.
+ * @param {string} keyEncoded The key, which must already be URI encoded.
+ * @param {*} value The value, which will be stringized and encoded (assumed
+ *     not already to be encoded).
+ * @return {string} The URI with the query parameter added.
+ */
+goog.uri.utils.setParam = function(uri, keyEncoded, value) {
+  return goog.uri.utils.appendParam(
+      goog.uri.utils.removeParam(uri, keyEncoded), keyEncoded, value);
+};
+
+
+/**
+ * Generates a URI path using a given URI and a path with checks to
+ * prevent consecutive "//". The baseUri passed in must not contain
+ * query or fragment identifiers. The path to append may not contain query or
+ * fragment identifiers.
+ *
+ * @param {string} baseUri URI to use as the base.
+ * @param {string} path Path to append.
+ * @return {string} Updated URI.
+ */
+goog.uri.utils.appendPath = function(baseUri, path) {
+  goog.uri.utils.assertNoFragmentsOrQueries_(baseUri);
+
+  // Remove any trailing '/'
+  if (goog.string.endsWith(baseUri, '/')) {
+    baseUri = baseUri.substr(0, baseUri.length - 1);
+  }
+  // Remove any leading '/'
+  if (goog.string.startsWith(path, '/')) {
+    path = path.substr(1);
+  }
+  return goog.string.buildString(baseUri, '/', path);
+};
+
+
+/**
+ * Replaces the path.
+ * @param {string} uri URI to use as the base.
+ * @param {string} path New path.
+ * @return {string} Updated URI.
+ */
+goog.uri.utils.setPath = function(uri, path) {
+  // Add any missing '/'.
+  if (!goog.string.startsWith(path, '/')) {
+    path = '/' + path;
+  }
+  var parts = goog.uri.utils.split(uri);
+  return goog.uri.utils.buildFromEncodedParts(
+      parts[goog.uri.utils.ComponentIndex.SCHEME],
+      parts[goog.uri.utils.ComponentIndex.USER_INFO],
+      parts[goog.uri.utils.ComponentIndex.DOMAIN],
+      parts[goog.uri.utils.ComponentIndex.PORT],
+      path,
+      parts[goog.uri.utils.ComponentIndex.QUERY_DATA],
+      parts[goog.uri.utils.ComponentIndex.FRAGMENT]);
+};
+
+
+/**
+ * Standard supported query parameters.
+ * @enum {string}
+ */
+goog.uri.utils.StandardQueryParam = {
+
+  /** Unused parameter for unique-ifying. */
+  RANDOM: 'zx'
+};
+
+
+/**
+ * Sets the zx parameter of a URI to a random value.
+ * @param {string} uri Any URI.
+ * @return {string} That URI with the "zx" parameter added or replaced to
+ *     contain a random string.
+ */
+goog.uri.utils.makeUnique = function(uri) {
+  return goog.uri.utils.setParam(uri,
+      goog.uri.utils.StandardQueryParam.RANDOM, goog.string.getRandomString());
+};