platform_system_core/libcutils/properties.cpp

145 lines
4.4 KiB
C++

/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "properties"
// #define LOG_NDEBUG 0
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <inttypes.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <cutils/properties.h>
#include <cutils/sockets.h>
#include <log/log.h>
int8_t property_get_bool(const char *key, int8_t default_value) {
if (!key) {
return default_value;
}
int8_t result = default_value;
char buf[PROPERTY_VALUE_MAX] = {'\0'};
int len = property_get(key, buf, "");
if (len == 1) {
char ch = buf[0];
if (ch == '0' || ch == 'n') {
result = false;
} else if (ch == '1' || ch == 'y') {
result = true;
}
} else if (len > 1) {
if (!strcmp(buf, "no") || !strcmp(buf, "false") || !strcmp(buf, "off")) {
result = false;
} else if (!strcmp(buf, "yes") || !strcmp(buf, "true") || !strcmp(buf, "on")) {
result = true;
}
}
return result;
}
// Convert string property to int (default if fails); return default value if out of bounds
static intmax_t property_get_imax(const char *key, intmax_t lower_bound, intmax_t upper_bound,
intmax_t default_value) {
if (!key) {
return default_value;
}
intmax_t result = default_value;
char buf[PROPERTY_VALUE_MAX] = {'\0'};
char *end = NULL;
int len = property_get(key, buf, "");
if (len > 0) {
int tmp = errno;
errno = 0;
// Infer base automatically
result = strtoimax(buf, &end, /*base*/ 0);
if ((result == INTMAX_MIN || result == INTMAX_MAX) && errno == ERANGE) {
// Over or underflow
result = default_value;
ALOGV("%s(%s,%" PRIdMAX ") - overflow", __FUNCTION__, key, default_value);
} else if (result < lower_bound || result > upper_bound) {
// Out of range of requested bounds
result = default_value;
ALOGV("%s(%s,%" PRIdMAX ") - out of range", __FUNCTION__, key, default_value);
} else if (end == buf) {
// Numeric conversion failed
result = default_value;
ALOGV("%s(%s,%" PRIdMAX ") - numeric conversion failed", __FUNCTION__, key,
default_value);
}
errno = tmp;
}
return result;
}
int64_t property_get_int64(const char *key, int64_t default_value) {
return (int64_t)property_get_imax(key, INT64_MIN, INT64_MAX, default_value);
}
int32_t property_get_int32(const char *key, int32_t default_value) {
return (int32_t)property_get_imax(key, INT32_MIN, INT32_MAX, default_value);
}
#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
#include <sys/_system_properties.h>
int property_set(const char *key, const char *value) {
return __system_property_set(key, value);
}
int property_get(const char *key, char *value, const char *default_value) {
int len = __system_property_get(key, value);
if (len > 0) {
return len;
}
if (default_value) {
len = strnlen(default_value, PROPERTY_VALUE_MAX - 1);
memcpy(value, default_value, len);
value[len] = '\0';
}
return len;
}
struct callback_data {
void (*callback)(const char* name, const char* value, void* cookie);
void* cookie;
};
static void trampoline(void* raw_data, const char* name, const char* value, unsigned /*serial*/) {
callback_data* data = reinterpret_cast<callback_data*>(raw_data);
data->callback(name, value, data->cookie);
}
static void property_list_callback(const prop_info* pi, void* data) {
__system_property_read_callback(pi, trampoline, data);
}
int property_list(void (*fn)(const char* name, const char* value, void* cookie), void* cookie) {
callback_data data = { fn, cookie };
return __system_property_foreach(property_list_callback, &data);
}