1 // Copyright 2017 The Abseil Authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "absl/strings/internal/str_format/output.h"
16
17 #include <errno.h>
18 #include <cstring>
19
20 namespace absl {
21 ABSL_NAMESPACE_BEGIN
22 namespace str_format_internal {
23
24 namespace {
25 struct ClearErrnoGuard {
ClearErrnoGuardabsl::str_format_internal::__anon03d0c7a20111::ClearErrnoGuard26 ClearErrnoGuard() : old_value(errno) { errno = 0; }
~ClearErrnoGuardabsl::str_format_internal::__anon03d0c7a20111::ClearErrnoGuard27 ~ClearErrnoGuard() {
28 if (!errno) errno = old_value;
29 }
30 int old_value;
31 };
32 } // namespace
33
Write(string_view v)34 void BufferRawSink::Write(string_view v) {
35 size_t to_write = std::min(v.size(), size_);
36 std::memcpy(buffer_, v.data(), to_write);
37 buffer_ += to_write;
38 size_ -= to_write;
39 total_written_ += v.size();
40 }
41
Write(string_view v)42 void FILERawSink::Write(string_view v) {
43 while (!v.empty() && !error_) {
44 // Reset errno to zero in case the libc implementation doesn't set errno
45 // when a failure occurs.
46 ClearErrnoGuard guard;
47
48 if (size_t result = std::fwrite(v.data(), 1, v.size(), output_)) {
49 // Some progress was made.
50 count_ += result;
51 v.remove_prefix(result);
52 } else {
53 if (errno == EINTR) {
54 continue;
55 } else if (errno) {
56 error_ = errno;
57 } else if (std::ferror(output_)) {
58 // Non-POSIX compliant libc implementations may not set errno, so we
59 // have check the streams error indicator.
60 error_ = EBADF;
61 } else {
62 // We're likely on a non-POSIX system that encountered EINTR but had no
63 // way of reporting it.
64 continue;
65 }
66 }
67 }
68 }
69
70 } // namespace str_format_internal
71 ABSL_NAMESPACE_END
72 } // namespace absl
73