terminal_position_lookup_table.cpp revision 2ac934296c0571ea252f3fb5a23fba29eb89c666 
1/*
2 * Copyright (C) 2013 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
17#include "suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table.h"
18
19#include "suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_reading_utils.h"
20#include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
21
22namespace latinime {
23
24int TerminalPositionLookupTable::getTerminalPtNodePosition(const int terminalId) const {
25    if (terminalId < 0 || terminalId >= mSize) {
26        return NOT_A_DICT_POS;
27    }
28    const int terminalPos = getBuffer()->readUint(
29            Ver4DictConstants::TERMINAL_ADDRESS_TABLE_ADDRESS_SIZE, getEntryPos(terminalId));
30    return (terminalPos == Ver4DictConstants::NOT_A_TERMINAL_ADDRESS) ?
31            NOT_A_DICT_POS : terminalPos;
32}
33
34bool TerminalPositionLookupTable::setTerminalPtNodePosition(
35        const int terminalId, const int terminalPtNodePos) {
36    if (terminalId < 0) {
37        return NOT_A_DICT_POS;
38    }
39    while (terminalId >= mSize) {
40        // Write new entry.
41        if (!getWritableBuffer()->writeUint(Ver4DictConstants::NOT_A_TERMINAL_ADDRESS,
42                Ver4DictConstants::TERMINAL_ADDRESS_TABLE_ADDRESS_SIZE, getEntryPos(mSize))) {
43            return false;
44        }
45        mSize++;
46    }
47    const int terminalPos = (terminalPtNodePos != NOT_A_DICT_POS) ?
48            terminalPtNodePos : Ver4DictConstants::NOT_A_TERMINAL_ADDRESS;
49    return getWritableBuffer()->writeUint(terminalPos,
50            Ver4DictConstants::TERMINAL_ADDRESS_TABLE_ADDRESS_SIZE, getEntryPos(terminalId));
51}
52
53bool TerminalPositionLookupTable::flushToFile(FILE *const file) const {
54    // If the used buffer size is smaller than the actual buffer size, regenerate the lookup
55    // table and write the new table to the file.
56    if (getEntryPos(mSize) < getBuffer()->getTailPosition()) {
57        TerminalPositionLookupTable lookupTableToWrite;
58        for (int i = 0; i < mSize; ++i) {
59            const int terminalPtNodePosition = getTerminalPtNodePosition(i);
60            if (!lookupTableToWrite.setTerminalPtNodePosition(i, terminalPtNodePosition)) {
61                AKLOGE("Cannot set terminal position to lookupTableToWrite."
62                        " terminalId: %d, position: %d", i, terminalPtNodePosition);
63                return false;
64            }
65        }
66        return lookupTableToWrite.flush(file);
67    } else {
68        // We can simply use this lookup table because the buffer size has not been
69        // changed.
70        return flush(file);
71    }
72}
73
74bool TerminalPositionLookupTable::runGCTerminalIds(TerminalIdMap *const terminalIdMap) {
75    int removedEntryCount = 0;
76    int nextNewTerminalId = 0;
77    for (int i = 0; i < mSize; ++i) {
78        const int terminalPos = getBuffer()->readUint(
79                Ver4DictConstants::TERMINAL_ADDRESS_TABLE_ADDRESS_SIZE, getEntryPos(i));
80        if (terminalPos == Ver4DictConstants::NOT_A_TERMINAL_ADDRESS) {
81            // This entry is a garbage.
82            removedEntryCount++;
83        } else {
84            // Give a new terminal id to the entry.
85            if (!getWritableBuffer()->writeUint(terminalPos,
86                    Ver4DictConstants::TERMINAL_ADDRESS_TABLE_ADDRESS_SIZE,
87                    getEntryPos(nextNewTerminalId))) {
88                return false;
89            }
90            // Memorize the mapping to the old terminal id to the new terminal id.
91            terminalIdMap->insert(TerminalIdMap::value_type(i, nextNewTerminalId));
92            nextNewTerminalId++;
93        }
94    }
95    mSize = nextNewTerminalId;
96    return true;
97}
98
99} // namespace latinime
100