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The Android Open Source Project9066cfe2009-03-03 19:31:44 -08001/* libs/opengles/Tokenizer.cpp
2**
3** Copyright 2006, The Android Open Source Project
4**
5** Licensed under the Apache License, Version 2.0 (the "License");
6** you may not use this file except in compliance with the License.
7** You may obtain a copy of the License at
8**
9** http://www.apache.org/licenses/LICENSE-2.0
10**
11** Unless required by applicable law or agreed to in writing, software
12** distributed under the License is distributed on an "AS IS" BASIS,
13** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14** See the License for the specific language governing permissions and
15** limitations under the License.
16*/
17
18#include <stdio.h>
19
20#include "Tokenizer.h"
21
22// ----------------------------------------------------------------------------
23
24namespace android {
25
26ANDROID_BASIC_TYPES_TRAITS(Tokenizer::run_t)
27
28Tokenizer::Tokenizer()
29{
30}
31
32Tokenizer::Tokenizer(const Tokenizer& other)
33 : mRanges(other.mRanges)
34{
35}
36
37Tokenizer::~Tokenizer()
38{
39}
40
41uint32_t Tokenizer::acquire()
42{
43 if (!mRanges.size() || mRanges[0].first) {
44 _insertTokenAt(0,0);
45 return 0;
46 }
47
48 // just extend the first run
49 const run_t& run = mRanges[0];
50 uint32_t token = run.first + run.length;
51 _insertTokenAt(token, 1);
52 return token;
53}
54
55bool Tokenizer::isAcquired(uint32_t token) const
56{
57 return (_indexOrderOf(token) >= 0);
58}
59
60status_t Tokenizer::reserve(uint32_t token)
61{
62 size_t o;
63 const ssize_t i = _indexOrderOf(token, &o);
64 if (i >= 0) {
65 return BAD_VALUE; // this token is already taken
66 }
67 ssize_t err = _insertTokenAt(token, o);
68 return (err<0) ? err : status_t(NO_ERROR);
69}
70
71status_t Tokenizer::release(uint32_t token)
72{
73 const ssize_t i = _indexOrderOf(token);
74 if (i >= 0) {
75 const run_t& run = mRanges[i];
76 if ((token >= run.first) && (token < run.first+run.length)) {
77 // token in this range, we need to split
78 run_t& run = mRanges.editItemAt(i);
79 if ((token == run.first) || (token == run.first+run.length-1)) {
80 if (token == run.first) {
81 run.first += 1;
82 }
83 run.length -= 1;
84 if (run.length == 0) {
85 // XXX: should we systematically remove a run that's empty?
86 mRanges.removeItemsAt(i);
87 }
88 } else {
89 // split the run
90 run_t new_run;
91 new_run.first = token+1;
92 new_run.length = run.first+run.length - new_run.first;
93 run.length = token - run.first;
94 mRanges.insertAt(new_run, i+1);
95 }
96 return NO_ERROR;
97 }
98 }
99 return NAME_NOT_FOUND;
100}
101
102ssize_t Tokenizer::_indexOrderOf(uint32_t token, size_t* order) const
103{
104 // binary search
105 ssize_t err = NAME_NOT_FOUND;
106 ssize_t l = 0;
107 ssize_t h = mRanges.size()-1;
108 ssize_t mid;
109 const run_t* a = mRanges.array();
110 while (l <= h) {
111 mid = l + (h - l)/2;
112 const run_t* const curr = a + mid;
113 int c = 0;
114 if (token < curr->first) c = 1;
115 else if (token >= curr->first+curr->length) c = -1;
116 if (c == 0) {
117 err = l = mid;
118 break;
119 } else if (c < 0) {
120 l = mid + 1;
121 } else {
122 h = mid - 1;
123 }
124 }
125 if (order) *order = l;
126 return err;
127}
128
129ssize_t Tokenizer::_insertTokenAt(uint32_t token, size_t index)
130{
131 const size_t c = mRanges.size();
132
133 if (index >= 1) {
134 // do we need to merge with the previous run?
135 run_t& p = mRanges.editItemAt(index-1);
136 if (p.first+p.length == token) {
137 p.length += 1;
138 if (index < c) {
139 const run_t& n = mRanges[index];
140 if (token+1 == n.first) {
141 p.length += n.length;
142 mRanges.removeItemsAt(index);
143 }
144 }
145 return index;
146 }
147 }
148
149 if (index < c) {
150 // do we need to merge with the next run?
151 run_t& n = mRanges.editItemAt(index);
152 if (token+1 == n.first) {
153 n.first -= 1;
154 n.length += 1;
155 return index;
156 }
157 }
158
159 return mRanges.insertAt(run_t(token,1), index);
160}
161
162void Tokenizer::dump() const
163{
164 const run_t* ranges = mRanges.array();
165 const size_t c = mRanges.size();
166 LOGD("Tokenizer (%p, size = %u)\n", this, c);
167 for (size_t i=0 ; i<c ; i++) {
168 LOGD("%u: (%u, %u)\n", i, ranges[i].first, ranges[i].length);
169 }
170}
171
172}; // namespace android
173