ARROW-631: [GLib] Import

See also https://issues.apache.org/jira/browse/ARROW-631 and `glib/README.md` in this change.

Author: Kouhei Sutou <[email protected]>

Closes apache#382 from kou/glib-import and squashes the following commits:

67a5d24 [Kouhei Sutou] [GLib] Rename directory to c_glib/ from glib/
24cd605 [Kouhei Sutou] [GLib] Import

.travis.yml

@@ -16,6 +16,9 @@ addons:
     - libboost-filesystem-dev
     - libboost-system-dev
     - libjemalloc-dev
+    - gtk-doc-tools
+    - autoconf-archive
+    - libgirepository1.0-dev
 
 matrix:
   fast_finish: true
@@ -30,9 +33,11 @@ matrix:
     - export CC="gcc-4.9"
     - export CXX="g++-4.9"
     - $TRAVIS_BUILD_DIR/ci/travis_before_script_cpp.sh
+    - $TRAVIS_BUILD_DIR/ci/travis_before_script_c_glib.sh
     script:
     - $TRAVIS_BUILD_DIR/ci/travis_script_cpp.sh
     - $TRAVIS_BUILD_DIR/ci/travis_script_python.sh
+    - $TRAVIS_BUILD_DIR/ci/travis_script_c_glib.sh
   - compiler: clang
     osx_image: xcode6.4
     os: osx

c_glib/.gitignore

@@ -0,0 +1,44 @@
+Makefile
+Makefile.in
+.deps/
+.libs/
+*.gir
+*.typelib
+*.o
+*.lo
+*.la
+*~
+/*.tar.gz
+/aclocal.m4
+/autom4te.cache/
+/config.h
+/config.h.in
+/config.log
+/config.status
+/config/
+/configure
+/doc/reference/*.txt
+/doc/reference/*.txt.bak
+/doc/reference/*.args
+/doc/reference/*.hierarchy
+/doc/reference/*.interfaces
+/doc/reference/*.prerequisites
+/doc/reference/*.signals
+/doc/reference/*.types
+/doc/reference/gtk-doc.make
+/doc/reference/*.stamp
+/doc/reference/html/
+/doc/reference/xml/
+/libtool
+/m4/
+/stamp-h1
+/version
+/arrow-glib/enums.c
+/arrow-glib/enums.h
+/arrow-glib/io-enums.c
+/arrow-glib/io-enums.h
+/arrow-glib/ipc-enums.c
+/arrow-glib/ipc-enums.h
+/arrow-glib/stamp-*
+/arrow-glib/*.pc
+/example/build

c_glib/Makefile.am

@@ -0,0 +1,26 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+ACLOCAL_AMFLAGS = -I m4 ${ACLOCAL_FLAGS}
+
+SUBDIRS =					\
+	arrow-glib				\
+	doc					\
+	example
+
+EXTRA_DIST =					\
+	version

c_glib/README.md

@@ -0,0 +1,114 @@
+<!---
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License. See accompanying LICENSE file.
+-->
+
+# Arrow GLib
+
+Arrow GLib is a wrapper library for Arrow C++. Arrow GLib provides C
+API.
+
+Arrow GLib supports
+[GObject Introspection](https://wiki.gnome.org/action/show/Projects/GObjectIntrospection).
+It means that you can create language bindings at runtime or compile time.
+
+For example, you can use Apache Arrow from Ruby by Arrow GLib and
+[gobject-introspection gem](https://rubygems.org/gems/gobject-introspection)
+with the following code:
+
+```ruby
+# Generate bindings at runtime
+require "gi"
+Arrow = GI.load("Arrow")
+
+# Now, you can access arrow::BooleanArray in Arrow C++ by
+# Arrow::BooleanArray
+p Arrow::BooleanArray
+```
+
+In Ruby case, you should use
+[red-arrow gem](https://rubygems.org/gems/red-arrow). It's based on
+gobject-introspection gem. It adds many convenient features to raw
+gobject-introspection gem based bindings.
+
+## Install
+
+### Package
+
+TODO
+
+### Build
+
+You need to install Arrow C++ before you install Arrow GLib. See Arrow
+C++ document about how to install Arrow C++.
+
+You need [GTK-Doc](https://www.gtk.org/gtk-doc/) and
+[GObject Introspection](https://wiki.gnome.org/action/show/Projects/GObjectIntrospection)
+to build Arrow GLib. You can install them by the followings:
+
+On Debian GNU/Linux or Ubuntu:
+
+```text
+% sudo apt install -y -V gtk-doc-tools libgirepository1.0-dev
+```
+
+On CentOS 7 or later:
+
+```text
+% sudo yum install -y gtk-doc gobject-introspection-devel
+```
+
+On macOS with [Homebrew](https://brew.sh/):
+
+```text
+% brew install -y gtk-doc gobject-introspection
+```
+
+Now, you can build Arrow GLib:
+
+```text
+% cd glib
+% ./configure --enable-gtk-doc
+% make
+% sudo make install
+```
+
+## Usage
+
+You can use Arrow GLib with C or other languages. If you use Arrow
+GLib with C, you use C API. If you use Arrow GLib with other
+languages, you use GObject Introspection based bindings.
+
+### C
+
+You can find API reference in the
+`/usr/local/share/gtk-doc/html/arrow-glib/` directory. If you specify
+`--prefix` to `configure`, the directory will be different.
+
+You can find example codes in the `example/` directory.
+
+### Language bindings
+
+You can use Arrow GLib with non C languages with GObject Introspection
+based bindings. Here are languages that support GObject Introspection:
+
+  * Ruby: [red-arrow gem](https://rubygems.org/gems/red-arrow) should be used.
+
+  * Python: [PyGObject](https://wiki.gnome.org/Projects/PyGObject) should be used. (Note that you should use PyArrow than Arrow GLib.)
+
+  * Lua: [LGI](https://github.com/pavouk/lgi) should be used.
+
+  * Go: [Go-gir-generator](https://github.com/linuxdeepin/go-gir-generator) should be used.
+
+See also
+[Projects/GObjectIntrospection/Users - GNOME Wiki!](https://wiki.gnome.org/Projects/GObjectIntrospection/Users)
+for other languages.