1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.net.http;
18
19import org.apache.http.util.CharArrayBuffer;
20import org.apache.http.protocol.HTTP;
21
22/**
23 * Utility methods for working on CharArrayBuffers.
24 *
25 * {@hide}
26 */
27class CharArrayBuffers {
28
29    static final char uppercaseAddon = 'a' - 'A';
30
31    /**
32     * Returns true if the buffer contains the given string. Ignores leading
33     * whitespace and case.
34     *
35     * @param buffer to search
36     * @param beginIndex index at which we should start
37     * @param str to search for
38     */
39    static boolean containsIgnoreCaseTrimmed(CharArrayBuffer buffer,
40            int beginIndex, final String str) {
41        int len = buffer.length();
42        char[] chars = buffer.buffer();
43        while (beginIndex < len && HTTP.isWhitespace(chars[beginIndex])) {
44            beginIndex++;
45        }
46        int size = str.length();
47        boolean ok = len >= beginIndex + size;
48        for (int j=0; ok && (j<size); j++) {
49            char a = chars[beginIndex+j];
50            char b = str.charAt(j);
51            if (a != b) {
52                a = toLower(a);
53                b = toLower(b);
54                ok = a == b;
55            }
56        }
57        return ok;
58    }
59
60    /**
61     * Returns index of first occurence ch. Lower cases characters leading up
62     * to first occurrence of ch.
63     */
64    static int setLowercaseIndexOf(CharArrayBuffer buffer, final int ch) {
65
66        int beginIndex = 0;
67        int endIndex = buffer.length();
68        char[] chars = buffer.buffer();
69
70        for (int i = beginIndex; i < endIndex; i++) {
71            char current = chars[i];
72            if (current == ch) {
73                return i;
74            } else if (current >= 'A' && current <= 'Z'){
75                // make lower case
76                current += uppercaseAddon;
77                chars[i] = current;
78            }
79        }
80        return -1;
81    }
82
83    private static char toLower(char c) {
84        if (c >= 'A' && c <= 'Z'){
85            c += uppercaseAddon;
86        }
87        return c;
88    }
89}
90