diff options
Diffstat (limited to 'mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/util/UriUtil.java')
| -rw-r--r-- | mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/util/UriUtil.java | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/util/UriUtil.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/util/UriUtil.java new file mode 100644 index 0000000000..03b5d26a51 --- /dev/null +++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/util/UriUtil.java @@ -0,0 +1,279 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * 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.mozilla.thirdparty.com.google.android.exoplayer2.util; + +import android.net.Uri; +import android.text.TextUtils; +import androidx.annotation.Nullable; + +/** + * Utility methods for manipulating URIs. + */ +public final class UriUtil { + + /** + * The length of arrays returned by {@link #getUriIndices(String)}. + */ + private static final int INDEX_COUNT = 4; + /** + * An index into an array returned by {@link #getUriIndices(String)}. + * <p> + * The value at this position in the array is the index of the ':' after the scheme. Equals -1 if + * the URI is a relative reference (no scheme). The hier-part starts at (schemeColon + 1), + * including when the URI has no scheme. + */ + private static final int SCHEME_COLON = 0; + /** + * An index into an array returned by {@link #getUriIndices(String)}. + * <p> + * The value at this position in the array is the index of the path part. Equals (schemeColon + 1) + * if no authority part, (schemeColon + 3) if the authority part consists of just "//", and + * (query) if no path part. The characters starting at this index can be "//" only if the + * authority part is non-empty (in this case the double-slash means the first segment is empty). + */ + private static final int PATH = 1; + /** + * An index into an array returned by {@link #getUriIndices(String)}. + * <p> + * The value at this position in the array is the index of the query part, including the '?' + * before the query. Equals fragment if no query part, and (fragment - 1) if the query part is a + * single '?' with no data. + */ + private static final int QUERY = 2; + /** + * An index into an array returned by {@link #getUriIndices(String)}. + * <p> + * The value at this position in the array is the index of the fragment part, including the '#' + * before the fragment. Equal to the length of the URI if no fragment part, and (length - 1) if + * the fragment part is a single '#' with no data. + */ + private static final int FRAGMENT = 3; + + private UriUtil() {} + + /** + * Like {@link #resolve(String, String)}, but returns a {@link Uri} instead of a {@link String}. + * + * @param baseUri The base URI. + * @param referenceUri The reference URI to resolve. + */ + public static Uri resolveToUri(@Nullable String baseUri, @Nullable String referenceUri) { + return Uri.parse(resolve(baseUri, referenceUri)); + } + + /** + * Performs relative resolution of a {@code referenceUri} with respect to a {@code baseUri}. + * + * <p>The resolution is performed as specified by RFC-3986. + * + * @param baseUri The base URI. + * @param referenceUri The reference URI to resolve. + */ + public static String resolve(@Nullable String baseUri, @Nullable String referenceUri) { + StringBuilder uri = new StringBuilder(); + + // Map null onto empty string, to make the following logic simpler. + baseUri = baseUri == null ? "" : baseUri; + referenceUri = referenceUri == null ? "" : referenceUri; + + int[] refIndices = getUriIndices(referenceUri); + if (refIndices[SCHEME_COLON] != -1) { + // The reference is absolute. The target Uri is the reference. + uri.append(referenceUri); + removeDotSegments(uri, refIndices[PATH], refIndices[QUERY]); + return uri.toString(); + } + + int[] baseIndices = getUriIndices(baseUri); + if (refIndices[FRAGMENT] == 0) { + // The reference is empty or contains just the fragment part, then the target Uri is the + // concatenation of the base Uri without its fragment, and the reference. + return uri.append(baseUri, 0, baseIndices[FRAGMENT]).append(referenceUri).toString(); + } + + if (refIndices[QUERY] == 0) { + // The reference starts with the query part. The target is the base up to (but excluding) the + // query, plus the reference. + return uri.append(baseUri, 0, baseIndices[QUERY]).append(referenceUri).toString(); + } + + if (refIndices[PATH] != 0) { + // The reference has authority. The target is the base scheme plus the reference. + int baseLimit = baseIndices[SCHEME_COLON] + 1; + uri.append(baseUri, 0, baseLimit).append(referenceUri); + return removeDotSegments(uri, baseLimit + refIndices[PATH], baseLimit + refIndices[QUERY]); + } + + if (referenceUri.charAt(refIndices[PATH]) == '/') { + // The reference path is rooted. The target is the base scheme and authority (if any), plus + // the reference. + uri.append(baseUri, 0, baseIndices[PATH]).append(referenceUri); + return removeDotSegments(uri, baseIndices[PATH], baseIndices[PATH] + refIndices[QUERY]); + } + + // The target Uri is the concatenation of the base Uri up to (but excluding) the last segment, + // and the reference. This can be split into 2 cases: + if (baseIndices[SCHEME_COLON] + 2 < baseIndices[PATH] + && baseIndices[PATH] == baseIndices[QUERY]) { + // Case 1: The base hier-part is just the authority, with an empty path. An additional '/' is + // needed after the authority, before appending the reference. + uri.append(baseUri, 0, baseIndices[PATH]).append('/').append(referenceUri); + return removeDotSegments(uri, baseIndices[PATH], baseIndices[PATH] + refIndices[QUERY] + 1); + } else { + // Case 2: Otherwise, find the last '/' in the base hier-part and append the reference after + // it. If base hier-part has no '/', it could only mean that it is completely empty or + // contains only one segment, in which case the whole hier-part is excluded and the reference + // is appended right after the base scheme colon without an added '/'. + int lastSlashIndex = baseUri.lastIndexOf('/', baseIndices[QUERY] - 1); + int baseLimit = lastSlashIndex == -1 ? baseIndices[PATH] : lastSlashIndex + 1; + uri.append(baseUri, 0, baseLimit).append(referenceUri); + return removeDotSegments(uri, baseIndices[PATH], baseLimit + refIndices[QUERY]); + } + } + + /** + * Removes query parameter from an Uri, if present. + * + * @param uri The uri. + * @param queryParameterName The name of the query parameter. + * @return The uri without the query parameter. + */ + public static Uri removeQueryParameter(Uri uri, String queryParameterName) { + Uri.Builder builder = uri.buildUpon(); + builder.clearQuery(); + for (String key : uri.getQueryParameterNames()) { + if (!key.equals(queryParameterName)) { + for (String value : uri.getQueryParameters(key)) { + builder.appendQueryParameter(key, value); + } + } + } + return builder.build(); + } + + /** + * Removes dot segments from the path of a URI. + * + * @param uri A {@link StringBuilder} containing the URI. + * @param offset The index of the start of the path in {@code uri}. + * @param limit The limit (exclusive) of the path in {@code uri}. + */ + private static String removeDotSegments(StringBuilder uri, int offset, int limit) { + if (offset >= limit) { + // Nothing to do. + return uri.toString(); + } + if (uri.charAt(offset) == '/') { + // If the path starts with a /, always retain it. + offset++; + } + // The first character of the current path segment. + int segmentStart = offset; + int i = offset; + while (i <= limit) { + int nextSegmentStart; + if (i == limit) { + nextSegmentStart = i; + } else if (uri.charAt(i) == '/') { + nextSegmentStart = i + 1; + } else { + i++; + continue; + } + // We've encountered the end of a segment or the end of the path. If the final segment was + // "." or "..", remove the appropriate segments of the path. + if (i == segmentStart + 1 && uri.charAt(segmentStart) == '.') { + // Given "abc/def/./ghi", remove "./" to get "abc/def/ghi". + uri.delete(segmentStart, nextSegmentStart); + limit -= nextSegmentStart - segmentStart; + i = segmentStart; + } else if (i == segmentStart + 2 && uri.charAt(segmentStart) == '.' + && uri.charAt(segmentStart + 1) == '.') { + // Given "abc/def/../ghi", remove "def/../" to get "abc/ghi". + int prevSegmentStart = uri.lastIndexOf("/", segmentStart - 2) + 1; + int removeFrom = prevSegmentStart > offset ? prevSegmentStart : offset; + uri.delete(removeFrom, nextSegmentStart); + limit -= nextSegmentStart - removeFrom; + segmentStart = prevSegmentStart; + i = prevSegmentStart; + } else { + i++; + segmentStart = i; + } + } + return uri.toString(); + } + + /** + * Calculates indices of the constituent components of a URI. + * + * @param uriString The URI as a string. + * @return The corresponding indices. + */ + private static int[] getUriIndices(String uriString) { + int[] indices = new int[INDEX_COUNT]; + if (TextUtils.isEmpty(uriString)) { + indices[SCHEME_COLON] = -1; + return indices; + } + + // Determine outer structure from right to left. + // Uri = scheme ":" hier-part [ "?" query ] [ "#" fragment ] + int length = uriString.length(); + int fragmentIndex = uriString.indexOf('#'); + if (fragmentIndex == -1) { + fragmentIndex = length; + } + int queryIndex = uriString.indexOf('?'); + if (queryIndex == -1 || queryIndex > fragmentIndex) { + // '#' before '?': '?' is within the fragment. + queryIndex = fragmentIndex; + } + // Slashes are allowed only in hier-part so any colon after the first slash is part of the + // hier-part, not the scheme colon separator. + int schemeIndexLimit = uriString.indexOf('/'); + if (schemeIndexLimit == -1 || schemeIndexLimit > queryIndex) { + schemeIndexLimit = queryIndex; + } + int schemeIndex = uriString.indexOf(':'); + if (schemeIndex > schemeIndexLimit) { + // '/' before ':' + schemeIndex = -1; + } + + // Determine hier-part structure: hier-part = "//" authority path / path + // This block can also cope with schemeIndex == -1. + boolean hasAuthority = schemeIndex + 2 < queryIndex + && uriString.charAt(schemeIndex + 1) == '/' + && uriString.charAt(schemeIndex + 2) == '/'; + int pathIndex; + if (hasAuthority) { + pathIndex = uriString.indexOf('/', schemeIndex + 3); // find first '/' after "://" + if (pathIndex == -1 || pathIndex > queryIndex) { + pathIndex = queryIndex; + } + } else { + pathIndex = schemeIndex + 1; + } + + indices[SCHEME_COLON] = schemeIndex; + indices[PATH] = pathIndex; + indices[QUERY] = queryIndex; + indices[FRAGMENT] = fragmentIndex; + return indices; + } + +} |