platform_bionic/libc/bionic/scandir.cpp
Elliott Hughes 76f8916b90 Clean up <stdlib.h> slightly.
Interestingly, this mostly involves cleaning up our implementation of
various <string.h> functions.

Change-Id: Ifaef49b5cb997134f7bc0cc31bdac844bdb9e089
2015-01-26 14:28:41 -08:00

118 lines
2.9 KiB
C++

/*
* Copyright (C) 2013 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.
*/
#include <dirent.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "private/bionic_macros.h"
#include "private/ScopedReaddir.h"
// A smart pointer to the scandir dirent**.
class ScandirResult {
public:
ScandirResult() : names_(NULL), size_(0), capacity_(0) {
}
~ScandirResult() {
while (size_ > 0) {
free(names_[--size_]);
}
free(names_);
}
size_t size() {
return size_;
}
dirent** release() {
dirent** result = names_;
names_ = NULL;
size_ = capacity_ = 0;
return result;
}
bool Add(dirent* entry) {
if (size_ >= capacity_) {
size_t new_capacity = capacity_ + 32;
dirent** new_names =
reinterpret_cast<dirent**>(realloc(names_, new_capacity * sizeof(dirent*)));
if (new_names == NULL) {
return false;
}
names_ = new_names;
capacity_ = new_capacity;
}
dirent* copy = CopyDirent(entry);
if (copy == NULL) {
return false;
}
names_[size_++] = copy;
return true;
}
void Sort(int (*comparator)(const dirent**, const dirent**)) {
// If we have entries and a comparator, sort them.
if (size_ > 0 && comparator != NULL) {
qsort(names_, size_, sizeof(dirent*),
reinterpret_cast<int (*)(const void*, const void*)>(comparator));
}
}
private:
dirent** names_;
size_t size_;
size_t capacity_;
static dirent* CopyDirent(dirent* original) {
// Allocate the minimum number of bytes necessary, rounded up to a 4-byte boundary.
size_t size = ((original->d_reclen + 3) & ~3);
dirent* copy = reinterpret_cast<dirent*>(malloc(size));
memcpy(copy, original, original->d_reclen);
return copy;
}
DISALLOW_COPY_AND_ASSIGN(ScandirResult);
};
int scandir(const char* dirname, dirent*** name_list,
int (*filter)(const dirent*),
int (*comparator)(const dirent**, const dirent**)) {
ScopedReaddir reader(dirname);
if (reader.IsBad()) {
return -1;
}
ScandirResult names;
dirent* entry;
while ((entry = reader.ReadEntry()) != NULL) {
// If we have a filter, skip names that don't match.
if (filter != NULL && !(*filter)(entry)) {
continue;
}
names.Add(entry);
}
names.Sort(comparator);
size_t size = names.size();
*name_list = names.release();
return size;
}
__strong_alias(scandir64, scandir);