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commit 05a6883ccdc6963f6cdb2438e2d86a7f847684fe
Author: Alan M. Carroll <a...@apache.org>
AuthorDate: Wed Jun 6 14:59:28 2018 -0500
BWF: Add errno support.
(cherry picked from commit 3d8ad11af446cffbc4ceb58a80b5604bdf391edb)
---
.../internal-libraries/buffer-writer.en.rst | 24 ++++
lib/ts/BufferWriterFormat.cc | 160 +++++++++++++++++++++
lib/ts/bwf_std_format.h | 14 ++
lib/ts/unit-tests/test_BufferWriterFormat.cc | 10 ++
4 files changed, 208 insertions(+)
diff --git a/doc/developer-guide/internal-libraries/buffer-writer.en.rst
b/doc/developer-guide/internal-libraries/buffer-writer.en.rst
index f8f19df..ced90d4 100644
--- a/doc/developer-guide/internal-libraries/buffer-writer.en.rst
+++ b/doc/developer-guide/internal-libraries/buffer-writer.en.rst
@@ -704,6 +704,30 @@ These are types for which there exists a type specific BWF
formatter.
bw.print("{:>20: =a}",addr); // -> " 172. 19. 3.105"
}
+Format Classes
+++++++++++++++
+
+Although the extension for a format can be overloaded to provide additional
features, this can become
+too confusing and complex to use if it is used for fundamentally different
semantics on the same
+based type. In that case it is better to provide a format wrapper class that
holds the base type
+but can be overloaded to produce different (wrapper class based) output. The
classic example is
+:code:`errno` which is an integral type but frequently should be formatted
with additional information
+such as the descriptive string for the value. To do this the format wrapper
class :code:`ts::bwf::Errno`
+is provided. Using it is simple::
+
+ w.print("File not open - {}", ts::bwf::Errno(errno));
+
+which will produce output that looks like
+
+ "File not open - EACCES: Permission denied [13]"
+
+For :code:`errno` this is handy in another way as :code:`ts::bwf::Errno` will
preserve the value of
+:code:`errno` across other calls that might change it. E.g.::
+
+ ts::bwf::Errno last_err(errno);
+ // some other code generating diagnostics that might tweak errno.
+ w.print("File not open - {}", last_err);
+
Global Names
++++++++++++
diff --git a/lib/ts/BufferWriterFormat.cc b/lib/ts/BufferWriterFormat.cc
index 4bdd507..18384c9 100644
--- a/lib/ts/BufferWriterFormat.cc
+++ b/lib/ts/BufferWriterFormat.cc
@@ -22,6 +22,7 @@
*/
#include <ts/BufferWriter.h>
+#include <ts/bwf_std_format.h>
#include <unistd.h>
#include <sys/param.h>
#include <cctype>
@@ -755,6 +756,164 @@ bwf_register_global(std::string_view name,
BWGlobalNameSignature formatter)
return ts::bw_fmt::BWF_GLOBAL_TABLE.emplace(name, formatter).second;
}
+BufferWriter &
+bwformat(BufferWriter &w, BWFSpec const &spec, bwf::Errno const &e)
+{
+ // Hand rolled, might not be totally compliant everywhere, but probably
close enough.
+ // The long string will be locally accurate.
+ // Clang requires the double braces. Why, Turing only knows.
+ static const std::array<std::string_view, 134> SHORT_NAME = {{
+ "SUCCESS: ",
+ "EPERM: ",
+ "ENOENT: ",
+ "ESRCH: ",
+ "EINTR: ",
+ "EIO: ",
+ "ENXIO: ",
+ "E2BIG ",
+ "ENOEXEC: ",
+ "EBADF: ",
+ "ECHILD: ",
+ "EAGAIN: ",
+ "ENOMEM: ",
+ "EACCES: ",
+ "EFAULT: ",
+ "ENOTBLK: ",
+ "EBUSY: ",
+ "EEXIST: ",
+ "EXDEV: ",
+ "ENODEV: ",
+ "ENOTDIR: ",
+ "EISDIR: ",
+ "EINVAL: ",
+ "ENFILE: ",
+ "EMFILE: ",
+ "ENOTTY: ",
+ "ETXTBSY: ",
+ "EFBIG: ",
+ "ENOSPC: ",
+ "ESPIPE: ",
+ "EROFS: ",
+ "EMLINK: ",
+ "EPIPE: ",
+ "EDOM: ",
+ "ERANGE: ",
+ "EDEADLK: ",
+ "ENAMETOOLONG: ",
+ "ENOLCK: ",
+ "ENOSYS: ",
+ "ENOTEMPTY: ",
+ "ELOOP: ",
+ "EWOULDBLOCK: ",
+ "ENOMSG: ",
+ "EIDRM: ",
+ "ECHRNG: ",
+ "EL2NSYNC: ",
+ "EL3HLT: ",
+ "EL3RST: ",
+ "ELNRNG: ",
+ "EUNATCH: ",
+ "ENOCSI: ",
+ "EL2HTL: ",
+ "EBADE: ",
+ "EBADR: ",
+ "EXFULL: ",
+ "ENOANO: ",
+ "EBADRQC: ",
+ "EBADSLT: ",
+ "EDEADLOCK: ",
+ "EBFONT: ",
+ "ENOSTR: ",
+ "ENODATA: ",
+ "ETIME: ",
+ "ENOSR: ",
+ "ENONET: ",
+ "ENOPKG: ",
+ "EREMOTE: ",
+ "ENOLINK: ",
+ "EADV: ",
+ "ESRMNT: ",
+ "ECOMM: ",
+ "EPROTO: ",
+ "EMULTIHOP: ",
+ "EDOTDOT: ",
+ "EBADMSG: ",
+ "EOVERFLOW: ",
+ "ENOTUNIQ: ",
+ "EBADFD: ",
+ "EREMCHG: ",
+ "ELIBACC: ",
+ "ELIBBAD: ",
+ "ELIBSCN: ",
+ "ELIBMAX: ",
+ "ELIBEXEC: ",
+ "EILSEQ: ",
+ "ERESTART: ",
+ "ESTRPIPE: ",
+ "EUSERS: ",
+ "ENOTSOCK: ",
+ "EDESTADDRREQ: ",
+ "EMSGSIZE: ",
+ "EPROTOTYPE: ",
+ "ENOPROTOOPT: ",
+ "EPROTONOSUPPORT: ",
+ "ESOCKTNOSUPPORT: ",
+ "EOPNOTSUPP: ",
+ "EPFNOSUPPORT: ",
+ "EAFNOSUPPORT: ",
+ "EADDRINUSE: ",
+ "EADDRNOTAVAIL: ",
+ "ENETDOWN: ",
+ "ENETUNREACH: ",
+ "ENETRESET: ",
+ "ECONNABORTED: ",
+ "ECONNRESET: ",
+ "ENOBUFS: ",
+ "EISCONN: ",
+ "ENOTCONN: ",
+ "ESHUTDOWN: ",
+ "ETOOMANYREFS: ",
+ "ETIMEDOUT: ",
+ "ECONNREFUSED: ",
+ "EHOSTDOWN: ",
+ "EHOSTUNREACH: ",
+ "EALREADY: ",
+ "EINPROGRESS: ",
+ "ESTALE: ",
+ "EUCLEAN: ",
+ "ENOTNAM: ",
+ "ENAVAIL: ",
+ "EISNAM: ",
+ "EREMOTEIO: ",
+ "EDQUOT: ",
+ "ENOMEDIUM: ",
+ "EMEDIUMTYPE: ",
+ "ECANCELED: ",
+ "ENOKEY: ",
+ "EKEYEXPIRED: ",
+ "EKEYREVOKED: ",
+ "EKEYREJECTED: ",
+ "EOWNERDEAD: ",
+ "ENOTRECOVERABLE: ",
+ "ERFKILL: ",
+ "EHWPOISON: ",
+ }};
+ // This provides convenient safe access to the errno short name array.
+ auto short_name = [](int n) { return n < static_cast<int>(SHORT_NAME.size())
? SHORT_NAME[n] : "Unknown: "sv; };
+ static const BWFormat number_fmt{"[{}]"sv}; // numeric value format.
+ if (spec.has_numeric_type()) { // if numeric type, print just
the numeric part.
+ w.print(number_fmt, e._e);
+ } else {
+ w.write(short_name(e._e));
+ w.write(strerror(e._e));
+ if (spec._type != 's' && spec._type != 'S') {
+ w.write(' ');
+ w.print(number_fmt, e._e);
+ }
+ }
+ return w;
+}
+
} // namespace ts
namespace
@@ -808,6 +967,7 @@ static bool BW_INITIALIZED __attribute__((unused)) = []()
-> bool {
ts::bw_fmt::BWF_GLOBAL_TABLE.emplace("thread-name", &BWF_ThreadName);
return true;
}();
+
} // namespace
namespace std
diff --git a/lib/ts/bwf_std_format.h b/lib/ts/bwf_std_format.h
index 9ea50a5..fdc998f 100644
--- a/lib/ts/bwf_std_format.h
+++ b/lib/ts/bwf_std_format.h
@@ -34,3 +34,17 @@ bwformat(ts::BufferWriter &w, ts::BWFSpec const &spec,
std::atomic<T> const &v)
return ts::bwformat(w, spec, v.load());
}
} // end namespace std
+
+namespace ts
+{
+namespace bwf
+{
+ struct Errno {
+ int _e;
+ explicit Errno(int e) : _e(e) {}
+ };
+} // namespace bwf
+
+BufferWriter &bwformat(BufferWriter &w, BWFSpec const &spec, bwf::Errno const
&e);
+
+} // namespace ts
diff --git a/lib/ts/unit-tests/test_BufferWriterFormat.cc
b/lib/ts/unit-tests/test_BufferWriterFormat.cc
index 14986f8..f1f5f3a 100644
--- a/lib/ts/unit-tests/test_BufferWriterFormat.cc
+++ b/lib/ts/unit-tests/test_BufferWriterFormat.cc
@@ -481,6 +481,16 @@ TEST_CASE("BWFormat floating", "[bwprint][bwformat]")
bw.reduce(0);
}
+TEST_CASE("bwstring std formats", "[libts][bwprint]")
+{
+ ts::LocalBufferWriter<120> w;
+
+ w.print("{}", ts::bwf::Errno(13));
+ REQUIRE(w.view() == "EACCES: Permission denied [13]"sv);
+ w.reset().print("{}", ts::bwf::Errno(134));
+ REQUIRE(w.view().substr(0, 22) == "Unknown: Unknown error"sv);
+}
+
// Normally there's no point in running the performance tests, but it's worth
keeping the code
// for when additional testing needs to be done.
#if 0
