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#include "common.hh"
#include "buffer.hh"
#include "io.hh"
#include "unique_fd.hh"
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <unistd.h>
namespace {
bool mkdirs_internal(int root, std::filesystem::path const& path, mode_t mode,
unique_fd* out) {
if (mkdirat(root, path.c_str(), mode) == 0) {
if (out)
*out = io::openat(root, path, io::open_flags::path |
io::open_flags::directory);
return true;
}
if (errno == EEXIST) {
struct stat buf;
if (fstatat(root, path.c_str(), &buf, 0))
return false;
if (!S_ISDIR(buf.st_mode))
return false;
if (out)
*out = io::openat(root, path,
io::open_flags::path | io::open_flags::directory);
return true;
}
if (errno != ENOENT)
return false;
auto parent = path.parent_path();
if (parent == path || !parent.has_relative_path())
return false;
unique_fd parent_fd;
if (!mkdirs_internal(root, parent, mode, &parent_fd))
return false;
auto name = path.filename();
if (mkdirat(parent_fd.get(), name.c_str(), mode))
return false;
if (out)
*out = io::openat(parent_fd.get(), name,
io::open_flags::path | io::open_flags::directory);
return true;
}
} // namespace
namespace io {
bool read_all(int fd, void* data, size_t size) {
auto* d = reinterpret_cast<char*>(data);
size_t offset = 0;
while (offset < size) {
auto got = read(fd, d + offset, size - offset);
if (got < 0) {
if (errno == EINTR)
continue;
return false;
}
if (got == 0)
return false;
offset += got;
}
return true;
}
bool write_all(int fd, void const* data, size_t size) {
auto* d = reinterpret_cast<char const*>(data);
size_t offset = 0;
while (offset < size) {
auto wrote = write(fd, d + offset, size - offset);
if (wrote < 0) {
if (errno == EINTR)
continue;
return false;
}
if (wrote == 0)
return false;
offset += wrote;
}
return true;
}
Return fill(int fd, Buffer* out, size_t buf_request_size,
size_t* bytes) {
if (bytes)
*bytes = 0;
while (true) {
size_t avail;
auto* ptr = out->wbuf(buf_request_size, avail);
if (avail == 0)
return Return::OK;
auto got = read(fd, ptr, avail);
if (got < 0) {
if (errno == EINTR)
continue;
if (errno == EAGAIN || errno == EWOULDBLOCK)
return Return::OK;
return Return::ERR;
}
if (got == 0)
return Return::CLOSED;
if (bytes)
*bytes += got;
out->wcommit(got);
// No point in trying again, will most likely get EAGAIN or EWOULDBLOCK.
// Might also be because the connection got closed, but we are in no hurry
// to find out so worth the not extra syscall at every read.
if (static_cast<size_t>(got) < avail)
return Return::OK;
}
}
bool drain(RoBuffer* in, int fd, size_t* bytes) {
if (bytes)
*bytes = 0;
while (true) {
size_t avail;
auto* ptr = in->rbuf(0, avail);
if (avail == 0)
return true;
auto wrote = write(fd, ptr, avail);
if (wrote < 0) {
if (errno == EINTR)
continue;
if (errno == EAGAIN || errno == EWOULDBLOCK)
return true;
return false;
}
if (wrote == 0)
return false;
if (bytes)
*bytes += wrote;
in->rcommit(wrote);
// No point in trying again, will most likely get EAGAIN or EWOULDBLOCK
if (static_cast<size_t>(wrote) < avail)
return true;
}
}
bool mkdirs(std::filesystem::path const& path, mode_t mode) {
return mkdirs(AT_FDCWD, path, mode);
}
bool mkdirs(int fd, std::filesystem::path const& path, mode_t mode) {
return mkdirs_internal(fd, path, mode, nullptr);
}
bool make_nonblocking(int fd) {
int status = fcntl(fd, F_GETFL, 0);
if (status == -1)
return false;
if ((status & O_NONBLOCK) == 0) {
if (fcntl(fd, F_SETFL, status | O_NONBLOCK))
return false;
}
return true;
}
unique_fd open(std::filesystem::path const& path, open_flags flags,
std::filesystem::perms perms) {
return openat(AT_FDCWD, path, flags, perms);
}
unique_fd openat(int fd, std::filesystem::path const& path, open_flags flags,
std::filesystem::perms perms) {
int posix_flags = O_RDONLY;
if ((flags & open_flags::wronly) == open_flags::wronly)
posix_flags |= O_WRONLY;
if ((flags & open_flags::rdwr) == open_flags::rdwr)
posix_flags |= O_RDWR;
if ((flags & open_flags::create) == open_flags::create)
posix_flags |= O_CREAT;
if ((flags & open_flags::excl) == open_flags::excl)
posix_flags |= O_EXCL;
if ((flags & open_flags::trunc) == open_flags::trunc)
posix_flags |= O_TRUNC;
if ((flags & open_flags::append) == open_flags::append)
posix_flags |= O_APPEND;
if ((flags & open_flags::directory) == open_flags::directory)
posix_flags |= O_DIRECTORY;
if ((flags & open_flags::path) == open_flags::path)
posix_flags |= O_PATH;
return unique_fd(::openat(fd, path.c_str(), posix_flags,
static_cast<mode_t>(perms)));
}
bool close(int fd) {
return ::close(fd) == 0;
}
ssize_t pread(int fd, void *buf, size_t count, off_t offset) {
return ::pread(fd, buf, count, offset);
}
ssize_t read(int fd, void *buf, size_t count) {
return ::read(fd, buf, count);
}
ssize_t write(int fd, const void *buf, size_t count) {
return ::write(fd, buf, count);
}
bool access(std::filesystem::path const& path, access_mode mode) {
int posix_mode;
if (mode == access_mode::exists) {
posix_mode = F_OK;
} else {
posix_mode = 0;
if ((mode & access_mode::read) == access_mode::read)
posix_mode |= R_OK;
if ((mode & access_mode::write) == access_mode::write)
posix_mode |= W_OK;
if ((mode & access_mode::exec) == access_mode::exec)
posix_mode |= X_OK;
}
return ::access(path.c_str(), posix_mode) == 0;
}
bool unlinkat(int fd, std::filesystem::path const& path) {
return ::unlinkat(fd, path.c_str(), 0) == 0;
}
bool fallocate(int fd, off_t offset, off_t len) {
return posix_fallocate(fd, offset, len) == 0;
}
} // namespace io
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