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#include "actual_function.h"
#include "utility/io.h"
#include "utility/logger.h"
#include "tracking/change_tracker.h"
// `true` signals the interposed functions to execute tracking logic
// `false` signals the interposed functions to do plain forwarding
static bool enabled = false;
static std::unique_ptr<utility::FileDescriptorGuard> fd_guard;
static std::unique_ptr<utility::Logger> logger;
static std::unique_ptr<tracking::ChangeTracker> tracker;
void init() __attribute__ ((constructor));
void init() {
if ( getenv("CHANGE_LOG_TARGET") != NULL ) {
fd_guard = std::make_unique<utility::FileDescriptorGuard>(
getenv("CHANGE_LOG_TARGET")
);
logger = std::make_unique<utility::Logger>(*fd_guard);
} else {
logger = std::make_unique<utility::Logger>(STDERR_FILENO);
}
if ( getenv("CHANGE_LOG_DIFF_CMD") != NULL ) {
tracker = std::make_unique<tracking::ChangeTracker>(
logger.get(), getenv("CHANGE_LOG_DIFF_CMD")
);
} else {
tracker = std::make_unique<tracking::ChangeTracker>(logger.get());
}
// tracking is only enabled when everything is initialized as both
// the actual tracking and the decision if a event should be tracked
// depend on `logger` and `tracker` being fully instantiated.
// In most cases this library will work correctly without delayed
// activation but e.g. `nvim` crashes as it performs tracked syscalls
// before `init` has been called.
enabled = true;
}
inline void track_write(const int fd) {
if ( enabled && fd != *fd_guard && utility::is_regular_file(fd) ) {
const std::string file_name{ utility::get_file_name(fd) };
if ( !tracker->is_tracked(file_name) ) {
tracker->track(file_name);
}
}
}
inline void track_rename(
const std::string& old_path, const std::string& new_path) {
if ( enabled ) {
if ( !tracker->is_tracked(old_path) ) {
tracker->track(old_path);
}
logger->append("renamed '", old_path, "' to '", new_path, "'");
}
}
inline void track_remove(const std::string& path) {
if ( enabled && utility::is_regular_file(path.c_str()) ) {
logger->append("removed '", path, "'");
}
}
ssize_t write(int fd, const void* buffer, size_t count) {
track_write(fd);
return actual::write(fd, buffer, count);
}
ssize_t writev(int fd, const iovec* iov, int iovcnt) {
track_write(fd);
return actual::writev(fd, iov, iovcnt);
}
void* mmap(void* addr, size_t length, int prot, int flags, int fd, off_t offset) {
if ( prot & PROT_WRITE ) {
track_write(fd);
}
return actual::mmap(addr, length, prot, flags, fd, offset);
}
int rename(const char* old_path, const char* new_path) {
track_rename(old_path, new_path);
return actual::rename(old_path, new_path);
}
int rmdir(const char* path) {
track_remove(path);
return actual::rmdir(path);
}
int unlink(const char* path) {
track_remove(path);
return actual::unlink(path);
}
int unlinkat(int dirfd, const char* path, int flags) {
if ( dirfd == AT_FDCWD ) {
track_remove(path);
} else {
track_remove(utility::get_file_name(dirfd) + path);
}
return actual::unlinkat(dirfd, path, flags);
}
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