1/*
2 * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package jdk.incubator.http;
27
28import java.util.Iterator;
29import java.util.Locale;
30import java.util.NoSuchElementException;
31
32/* This is useful for the nightmare of parsing multi-part HTTP/RFC822 headers
33 * sensibly:
34 * From a String like: 'timeout=15, max=5'
35 * create an array of Strings:
36 * { {"timeout", "15"},
37 *   {"max", "5"}
38 * }
39 * From one like: 'Basic Realm="FuzzFace" Foo="Biz Bar Baz"'
40 * create one like (no quotes in literal):
41 * { {"basic", null},
42 *   {"realm", "FuzzFace"}
43 *   {"foo", "Biz Bar Baz"}
44 * }
45 * keys are converted to lower case, vals are left as is....
46 */
47class HeaderParser {
48
49    /* table of key/val pairs */
50    String raw;
51    String[][] tab;
52    int nkeys;
53    int asize = 10; // initial size of array is 10
54
55    public HeaderParser(String raw) {
56        this.raw = raw;
57        tab = new String[asize][2];
58        parse();
59    }
60
61    private HeaderParser () { }
62
63    /**
64     * Creates a new HeaderParser from this, whose keys (and corresponding
65     * values) range from "start" to "end-1"
66     */
67    public HeaderParser subsequence(int start, int end) {
68        if (start == 0 && end == nkeys) {
69            return this;
70        }
71        if (start < 0 || start >= end || end > nkeys) {
72            throw new IllegalArgumentException("invalid start or end");
73        }
74        HeaderParser n = new HeaderParser();
75        n.tab = new String [asize][2];
76        n.asize = asize;
77        System.arraycopy (tab, start, n.tab, 0, (end-start));
78        n.nkeys= (end-start);
79        return n;
80    }
81
82    private void parse() {
83
84        if (raw != null) {
85            raw = raw.trim();
86            char[] ca = raw.toCharArray();
87            int beg = 0, end = 0, i = 0;
88            boolean inKey = true;
89            boolean inQuote = false;
90            int len = ca.length;
91            while (end < len) {
92                char c = ca[end];
93                if ((c == '=') && !inQuote) { // end of a key
94                    tab[i][0] = new String(ca, beg, end-beg).toLowerCase(Locale.US);
95                    inKey = false;
96                    end++;
97                    beg = end;
98                } else if (c == '\"') {
99                    if (inQuote) {
100                        tab[i++][1]= new String(ca, beg, end-beg);
101                        inQuote=false;
102                        do {
103                            end++;
104                        } while (end < len && (ca[end] == ' ' || ca[end] == ','));
105                        inKey=true;
106                        beg=end;
107                    } else {
108                        inQuote=true;
109                        end++;
110                        beg=end;
111                    }
112                } else if (c == ' ' || c == ',') { // end key/val, of whatever we're in
113                    if (inQuote) {
114                        end++;
115                        continue;
116                    } else if (inKey) {
117                        tab[i++][0] = (new String(ca, beg, end-beg)).toLowerCase(Locale.US);
118                    } else {
119                        tab[i++][1] = (new String(ca, beg, end-beg));
120                    }
121                    while (end < len && (ca[end] == ' ' || ca[end] == ',')) {
122                        end++;
123                    }
124                    inKey = true;
125                    beg = end;
126                } else {
127                    end++;
128                }
129                if (i == asize) {
130                    asize = asize * 2;
131                    String[][] ntab = new String[asize][2];
132                    System.arraycopy (tab, 0, ntab, 0, tab.length);
133                    tab = ntab;
134                }
135            }
136            // get last key/val, if any
137            if (--end > beg) {
138                if (!inKey) {
139                    if (ca[end] == '\"') {
140                        tab[i++][1] = (new String(ca, beg, end-beg));
141                    } else {
142                        tab[i++][1] = (new String(ca, beg, end-beg+1));
143                    }
144                } else {
145                    tab[i++][0] = (new String(ca, beg, end-beg+1)).toLowerCase();
146                }
147            } else if (end == beg) {
148                if (!inKey) {
149                    if (ca[end] == '\"') {
150                        tab[i++][1] = String.valueOf(ca[end-1]);
151                    } else {
152                        tab[i++][1] = String.valueOf(ca[end]);
153                    }
154                } else {
155                    tab[i++][0] = String.valueOf(ca[end]).toLowerCase();
156                }
157            }
158            nkeys=i;
159        }
160    }
161
162    public String findKey(int i) {
163        if (i < 0 || i > asize) {
164            return null;
165        }
166        return tab[i][0];
167    }
168
169    public String findValue(int i) {
170        if (i < 0 || i > asize) {
171            return null;
172        }
173        return tab[i][1];
174    }
175
176    public String findValue(String key) {
177        return findValue(key, null);
178    }
179
180    public String findValue(String k, String Default) {
181        if (k == null) {
182            return Default;
183        }
184        k = k.toLowerCase(Locale.US);
185        for (int i = 0; i < asize; ++i) {
186            if (tab[i][0] == null) {
187                return Default;
188            } else if (k.equals(tab[i][0])) {
189                return tab[i][1];
190            }
191        }
192        return Default;
193    }
194
195    class ParserIterator implements Iterator<String> {
196        int index;
197        boolean returnsValue; // or key
198
199        ParserIterator (boolean returnValue) {
200            returnsValue = returnValue;
201        }
202        @Override
203        public boolean hasNext () {
204            return index<nkeys;
205        }
206        @Override
207        public String next () {
208            if (index >= nkeys) {
209                throw new NoSuchElementException();
210            }
211            return tab[index++][returnsValue?1:0];
212        }
213    }
214
215    public Iterator<String> keys () {
216        return new ParserIterator (false);
217    }
218
219    public Iterator<String> values () {
220        return new ParserIterator (true);
221    }
222
223    @Override
224    public String toString () {
225        Iterator<String> k = keys();
226        StringBuilder sb = new StringBuilder();
227        sb.append("{size=").append(asize).append(" nkeys=").append(nkeys)
228                .append(' ');
229        for (int i=0; k.hasNext(); i++) {
230            String key = k.next();
231            String val = findValue (i);
232            if (val != null && "".equals (val)) {
233                val = null;
234            }
235            sb.append(" {").append(key).append(val == null ? "" : "," + val)
236                    .append('}');
237            if (k.hasNext()) {
238                sb.append (',');
239            }
240        }
241        sb.append (" }");
242        return sb.toString();
243    }
244
245    public int findInt(String k, int Default) {
246        try {
247            return Integer.parseInt(findValue(k, String.valueOf(Default)));
248        } catch (Throwable t) {
249            return Default;
250        }
251    }
252}
253