ruby: add extension using the C library

Pierre-Alexandre Meyer · Pierre-Alexandre Meyer · commit 00c4be981a0d · 2011-07-20T10:14:10.000-07:00
To use it:

DYLD_INSERT_LIBRARIES=./c/.libs/libsmile_decode-1.0.0.dylib irb

&gt; require 'smile'
&gt; p = Smile::Parser.new("data.smile")
&gt; puts p.check_header
 =&gt; true

Signed-off-by: Pierre-Alexandre Meyer &lt;pierre@ning.com&gt;
diff --git a/.gitignore b/.gitignore
@@ -1,5 +1,5 @@
 .sconsign.dblite
-smile
+c/smile
 a.out
 *.c.out
 *.o
@@ -22,3 +22,13 @@ config.status
 c/src/.dirstamp
 c/src/.deps
 Makefile
+mkmf.log
+.libs/
+config.guess
+config.sub
+*.la
+*.so
+libtool
+ltmain.sh
+*.lo
+*.bundle
diff --git a/c/Makefile.am b/c/Makefile.am
@@ -2,4 +2,8 @@ AUTOMAKE_OPTIONS = subdir-objects
 ACLOCAL_AMFLAGS = ${ACLOCAL_FLAGS}
 
 bin_PROGRAMS = smile
-smile_SOURCES = src/smile_decode.h src/smile_decode.c src/printer.h src/printer.c src/api.h
+smile_SOURCES = src/printer.c
+smile_LDADD = libsmile_decode
+
+lib_LTLIBRARIES = libsmile_decode-1.0.la
+libsmile_decode_1_0_la_SOURCES = src/smile_decode.c
diff --git a/c/configure.ac b/c/configure.ac
@@ -12,6 +12,7 @@ AC_PROG_CC
 AM_PROG_CC_C_O
 
 # Checks for libraries.
+AC_PROG_LIBTOOL
 
 # Checks for header files.
 AC_CHECK_HEADERS([fcntl.h limits.h stdlib.h string.h unistd.h])
diff --git a/ruby/src/extconf.rb b/ruby/src/extconf.rb
@@ -0,0 +1,17 @@
+# Loads mkmf which is used to make makefiles for Ruby extensions
+require 'mkmf'
+
+extension_name = "smile"
+
+unless $CFLAGS.gsub!(/ -O[\dsz]?/, ' -O3')
+  $CFLAGS << ' -O3'
+end
+if CONFIG['CC'] =~ /gcc/
+  $CFLAGS << ' -Wall -Werror'
+end
+
+dir_config(extension_name, "../../c/src", "../../c/src")
+find_header("smile_decode.h")
+find_library("smile_decode", "smile_decode_header")
+
+create_makefile(extension_name)
diff --git a/ruby/src/smile.c b/ruby/src/smile.c
@@ -0,0 +1,64 @@
+#include "ruby.h"
+
+#include "smile_decode.h"
+
+static VALUE rb_mSmile;
+static VALUE rb_cParser;
+
+static FILE* file;
+
+static void file_mark(FILE *f)
+{
+  /* Nothing needed */
+}
+
+static void file_free(FILE *f)
+{
+    if (f) {
+        fclose(f);
+    }
+}
+
+static VALUE file_alloc(VALUE klass)
+{
+    FILE *f = NULL;
+    return Data_Wrap_Struct(klass, file_mark, file_free, f);
+}
+static VALUE file_init(VALUE obj, VALUE path)
+{
+    file = fopen(RSTRING(path)->ptr, "r");
+
+    if (file == NULL) {
+        rb_raise(rb_eRuntimeError, "Invalid file specified");
+    }
+
+    return Qnil;
+}
+
+static VALUE check_header(VALUE self)
+{
+    u8 header[4];
+
+    int bytes_read = fread(header, sizeof(header), 4, file);
+
+    if (bytes_read != 4) {
+        rb_raise(rb_eRuntimeError, "Could not read header");
+        return Qfalse;
+    } else {
+        if (smile_decode_header(header)) {
+            return Qtrue;
+        } else {
+            return Qfalse;
+        }
+    }
+}
+
+void Init_smile()
+{
+  rb_mSmile = rb_define_module("Smile");
+  rb_cParser = rb_define_class_under(rb_mSmile, "Parser", rb_cObject);
+  rb_define_alloc_func(rb_cParser, file_alloc);
+  rb_define_method(rb_cParser, "initialize", file_init, 1);
+
+  rb_define_method(rb_cParser, "check_header", check_header, 0);
+}
