Initial release

.gitignore

+# Matches ALL Makefile and Makefile.in occurrences
+Makefile
+Makefile.in
+
+# ...
+_*
+.deps/
+.libs/
+*.o
+*.a
+*.lo
+*.la
+*~
+*.sw[op]
+*.trs
+*.log
+
+# Various auto-tools artifacts
+/aclocal.m4
+/autom4te.cache/
+/build-aux
+/compile
+/config.guess
+/config.h
+/config.h.in
+/config.status
+/config.sub
+/configure
+/configure.lineno
+/depcomp
+/install-sh
+/libtool
+/ltmain.sh
+/m4/libtool.m4
+/m4/ltoptions.m4
+/m4/ltsugar.m4
+/m4/ltversion.m4
+/m4/lt~obsolete.m4
+/missing
+/stamp-h1
+TAGS
+tags
+cscope.*out
+.dirstamp
+test-driver
+
+# our binary
+elbestream
+# man
+elbestream.1
+
+# dist
+elbestream-*.tar.gz

CONTRIBUTING.rst

+CONTRIBUTING
+============
+
+To contribute code or documentation, submit a `merge request
+<https://gitlab.com/uplex/misc/elbestream/-/merge_requests>`_.
+
+If you have a problem or discover a bug, you can post an `issue
+<https://gitlab.com/uplex/misc/elbestream/-/issues>`_.
+

INSTALL.rst

+INSTALLATION
+============
+
+Building from source
+~~~~~~~~~~~~~~~~~~~~
+
+This tool should build like any other autotools-supported tool::
+
+    ./autogen.sh
+    ./configure
+    make
+    make check
+    sudo make install
+
+The ``./autogen.sh`` step is only needed when building from the git
+repository.

LICENSE

+Copyright 2021 UPLEX Nils Goroll Systemoptimierung
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.

Makefile.am

+ACLOCAL_AMFLAGS = -I m4
+
+bin_PROGRAMS = elbestream
+
+elbestream_SOURCES = elbestream.c
+
+TESTS = test.sh
+
+EXTRA_DIST = README.rst LICENSE CONTRIBUTING.rst INSTALL.rst test.sh
+
+doc_DATA = README.rst LICENSE CONTRIBUTING.rst INSTALL.rst
+
+elbestream.1: README.rst
+	$(AM_V_GEN) $(RST2MAN) $< $@
+
+%.1 %.2 %.3 %.4 %.5 %.6 %.7 %.8 %.9:
+if HAVE_RST2MAN
+	${RST2MAN} $< $@
+else
+	@echo "========================================"
+	@echo "You need rst2man installed to make dist"
+	@echo "========================================"
+	@false
+endif
+
+.PHONY: fint
+
+flint: flint.lnt elbestream.c
+	flexelint flint.lnt elbestream.c

README.rst

+==========
+ELBEstream
+==========
+
+---------------------------
+Error Latched BuffEr stream
+---------------------------
+
+:Manual section: 1
+
+SYNOPSIS
+========
+
+::
+
+   ./elbestream
+	[-i <input buffer size> (default: 1048576 bytes)]
+	[-o <output buffer size> (default: 1048576 bytes)]
+	[-m <minimum output size>]
+	--   try command ...
+	---- fin command ...
+
+*fin command* needs to contain one ``%f`` argument which is replaced
+by a filename which *fin command* should read input data from.
+
+EXAMPLE
+-------
+
+::
+
+   ./elbestream -m 131 \
+     --   /usr/bin/ffmpeg -i - -ac 2 -f wav pipe:1 \
+     ---- /usr/bin/ffmpeg -i %f -ac 2 -f wav pipe:1
+
+DESCRIPTION
+===========
+
+Programs which usually work in *streaming* mode, taking their input
+from `stdin(3)` and writing to `stdout(3)` might fail for some inputs.
+
+For example,
+
+::
+
+  /usr/bin/ffmpeg -i - -ac 2 -f wav pipe:1 <FILE.aac >t.wav
+
+might throw errors like::
+
+  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x560855efb900] stream 0, offset 0x28: partial file
+  pipe:: Invalid data found when processing input
+  ...
+  Output file is empty, nothing was encoded (check -ss / -t / -frames parameters if used)
+
+while::
+
+  /usr/bin/ffmpeg -i FILE.aac -ac 2 -f wav pipe:1 >t.wav
+
+works just fine.
+
+This program aims to solve this case like these in a generic,
+efficient manner, trying to use the *streaming* case whenever possible
+and only failing back to a buffered file mode if necessary.
+
+First, the input buffer is filled from `stdin(3)`.
+
+Next, *try command* is executed on the input buffer with its output
+buffered. Once either all of the input buffer has been written to *try
+command*, or the output buffer is full, it is determined if the
+program is classified as failed or considered successful (so far,
+because not all input has necessarily been processed).
+
+* Obviously, if the *try command* process has exited with failure, it
+  is considered to have failed.
+
+* Also, if it has not output at least as many bytes as specified by
+  the ``-m`` argument, it is considered to have failed and gets
+  terminated by elbestream.
+
+If *try command* has not failed by these checks, it is left running
+on the remainder of `stdin(3)`, with its output being sent to
+`stdout(3)` as if only *try command* was run to begin with.
+
+If, however, *try command* is considered to have failed, the input
+buffer and the rest of `stdin(3)` are written to a temporary
+file. Then, the ``%f`` argument of *fin command* is replaced with the
+name of that file and *fin command* is run.
+
+IMPLEMENTATION DETAILS
+======================
+
+This tool uses the `splice(2)` and `vmsplice(2)` systemcalls on Linux
+if they are available and usable on the respective file descriptors in
+an attempt to reduce overhead of the I/O operations involved. It falls
+back to ordinary `read(2)`\ /\ `write(2)` loops.
+
+INSTALLATION
+============
+
+See `INSTALL.rst <INSTALL.rst>`_ in the source repository.
+
+SUPPORT
+=======
+
+For community support, please use `Gitlab Issues`_.
+
+For commercial support, please contact info@uplex.de
+
+.. _Gitlab Issues: https://gitlab.com/uplex/misc/elbestream/-/issues
+
+COPYRIGHT
+=========
+
+::
+
+  Copyright 2021 UPLEX Nils Goroll Systemoptimierung
+  All rights reserved
+
+  Author: Nils Goroll <nils.goroll@uplex.de>
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions
+  are met:
+  1. Redistributions of source code must retain the above copyright
+     notice, this list of conditions and the following disclaimer.
+  2. Redistributions in binary form must reproduce the above copyright
+     notice, this list of conditions and the following disclaimer in the
+     documentation and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+  ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+  SUCH DAMAGE.

autogen.sh

+#!/bin/sh
+#
+# Use autogen.des when doing code development
+
+autoreconf -i

configure.ac

+AC_PREREQ(2.68)
+AC_COPYRIGHT([Copyright 2021  UPLEX - Nils Goroll Systemoptimierung])
+AC_INIT([elbestream], [trunk], [varnish-support@uplex.de], [elbestream])
+AC_CONFIG_MACRO_DIR([m4])
+AC_CONFIG_SRCDIR(elbestream.c)
+AM_CONFIG_HEADER(config.h)
+AC_CANONICAL_SYSTEM
+AC_LANG(C)
+
+AM_INIT_AUTOMAKE([1.12 -Wall -Werror foreign parallel-tests])
+AM_SILENT_RULES([yes])
+
+AC_PROG_CC
+AC_PROG_CC_STDC
+if test "x$ac_cv_prog_cc_c99" = xno; then
+	AC_MSG_ERROR([Could not find a C99 compatible compiler])
+fi
+AC_PROG_CPP
+
+AX_PTHREAD(,[AC_MSG_ERROR([Could not configure pthreads support])])
+
+LIBS="$PTHREAD_LIBS $LIBS"
+CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+CC="$PTHREAD_CC"
+
+AC_ARG_WITH([rst2man],
+	AS_HELP_STRING(
+		[--with-rst2man=PATH],
+		[Location of rst2man (auto)]),
+	[RST2MAN="$withval"],
+	AC_CHECK_PROGS(RST2MAN, [rst2man rst2man.py], []))
+AM_CONDITIONAL(HAVE_RST2MAN, [test "x$RST2MAN" != "xno"])
+
+AC_CHECK_FUNCS([splice vmsplice])
+AC_CONFIG_FILES([
+	Makefile
+])
+AC_OUTPUT

flint.lnt

+-e717    // do ... while(1) ...
+-e716         // while(1) ...

test.sh

+#!/bin/bash
+
+set -eux
+
+t=$(date)
+for i in 1 4 10 29 30 31 40 ; do
+    for o in 1 4 10 29 30 31 40 ; do
+	r=$(echo "${t}" | ./elbestream -i $i -o $o -- /usr/bin/cat \
+				  ---- /usr/bin/cat %f)
+	if [[ "${r}" != "${t}" ]] ; then
+	    echo >&2 FAIL
+	    exit 9
+	fi
+	r=$(echo "${t}" | ./elbestream -i $i -o $o -m 1 -- /bin/false \
+				  ---- /usr/bin/cat %f)
+	if [[ "${r}" != "${t}" ]] ; then
+	    echo >&2 FAIL
+	    exit 9
+	fi
+    done
+done