1/*
2 * Copyright (C) 2016 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 "proto_format.h"
18
19#include <string.h>
20
21extern int const PROTO_FORMAT_STRING_POOL_SIZE;
22extern int const PROTO_FORMAT_ENUM_LABELS_LENGTH;
23extern int const PROTO_FORMAT_MESSAGES_LENGTH;
24extern int const PROTO_FORMAT_FIELDS_LENGTH;
25
26extern char const PROTO_FORMAT_STRING_POOL[];
27extern ProtoFieldFormat const PROTO_FORMAT_FIELDS[];
28extern ProtoEnumLabel const PROTO_FORMAT_ENUM_LABELS[];
29extern ProtoMessageFormat const PROTO_FORMAT_MESSAGES[];
30
31static const char*
32get_string(int index)
33{
34    if (index >= 0 && index < PROTO_FORMAT_STRING_POOL_SIZE) {
35        return PROTO_FORMAT_STRING_POOL + index;
36    } else {
37        // These indices all come from within the generated table, so just crash now.
38        *(int*)NULL = 42;
39        return NULL;
40    }
41}
42
43static ProtoMessageFormat const*
44get_message(int index)
45{
46    if (index >= 0 && index < PROTO_FORMAT_MESSAGES_LENGTH) {
47        return PROTO_FORMAT_MESSAGES + index;
48    } else {
49        // These indices all come from within the generated table, so just crash now.
50        *(int*)NULL = 42;
51        return NULL;
52    }
53}
54
55static int
56compare_name(const char* full, const char* package, const char* clazz)
57{
58    int const packageLen = strlen(package);
59    int cmp = strncmp(full, package, packageLen);
60    if (cmp == 0) {
61        cmp = full[packageLen] - '.';
62        if (cmp == 0) {
63            return strcmp(full + packageLen, clazz);
64        }
65    }
66    return cmp;
67}
68
69int
70find_message_index(const char* name)
71{
72    size_t low = 0;
73    size_t high = PROTO_FORMAT_FIELDS_LENGTH - 1;
74
75    while (low <= high) {
76        size_t mid = (low + high) >> 1;
77        ProtoMessageFormat const* msg = get_message(mid);
78
79        int cmp = compare_name(name, get_string(msg->package_name), get_string(msg->package_name));
80        if (cmp < 0) {
81            low = mid + 1;
82        } else if (cmp > 0) {
83            high = mid - 1;
84        } else {
85            return mid;
86        }
87    }
88    return -1;
89}
90