Fresh start

3 files changed, 1598 insertions, 0 deletions

diff --git a/jni/ruby/ext/dbm/Makefile b/jni/ruby/ext/dbm/Makefile
new file mode 100644
index 0000000..dc3421d
--- /dev/null
+++ b/jni/ruby/ext/dbm/Makefile
@@ -0,0 +1,150 @@
+# ***DUMMY MAKEFILE***
+
+SHELL = /bin/sh
+
+# V=0 quiet, V=1 verbose.  other values don't work.
+V = 0
+Q1 = $(V:1=)
+Q = $(Q1:0=@)
+ECHO1 = $(V:1=@:)
+ECHO = $(ECHO1:0=@echo)
+NULLCMD = :
+
+#### Start of system configuration section. ####
+top_srcdir = $(topdir)/.
+srcdir = $(top_srcdir)/ext/dbm
+topdir = ../..
+hdrdir = $(top_srcdir)/include
+arch_hdrdir = $(extout)/include/$(arch)
+PATH_SEPARATOR = :
+VPATH = $(srcdir):$(arch_hdrdir)/ruby:$(hdrdir)/ruby
+RUBYLIB =
+RUBYOPT = -
+prefix = $(DESTDIR)/usr/local
+rubysitearchprefix = $(rubylibprefix)/$(sitearch)
+rubyarchprefix = $(rubylibprefix)/$(arch)
+rubylibprefix = $(libdir)/$(RUBY_BASE_NAME)
+exec_prefix = $(prefix)
+vendorarchhdrdir = $(vendorhdrdir)/$(sitearch)
+sitearchhdrdir = $(sitehdrdir)/$(sitearch)
+rubyarchhdrdir = $(rubyhdrdir)/$(arch)
+vendorhdrdir = $(rubyhdrdir)/vendor_ruby
+sitehdrdir = $(rubyhdrdir)/site_ruby
+rubyhdrdir = $(includedir)/$(RUBY_VERSION_NAME)
+vendorarchdir = $(vendorlibdir)/$(sitearch)
+vendorlibdir = $(vendordir)/$(ruby_version)
+vendordir = $(rubylibprefix)/vendor_ruby
+sitearchdir = $(sitelibdir)/$(sitearch)
+sitelibdir = $(sitedir)/$(ruby_version)
+sitedir = $(rubylibprefix)/site_ruby
+rubyarchdir = $(rubylibdir)/$(arch)
+rubylibdir = $(rubylibprefix)/$(ruby_version)
+sitearchincludedir = $(includedir)/$(sitearch)
+archincludedir = $(includedir)/$(arch)
+sitearchlibdir = $(libdir)/$(sitearch)
+archlibdir = $(libdir)/$(arch)
+ridir = $(datarootdir)/$(RI_BASE_NAME)
+mandir = $(datarootdir)/man
+localedir = $(datarootdir)/locale
+libdir = $(exec_prefix)/lib
+psdir = $(docdir)
+pdfdir = $(docdir)
+dvidir = $(docdir)
+htmldir = $(docdir)
+infodir = $(datarootdir)/info
+docdir = $(datarootdir)/doc/$(PACKAGE)
+oldincludedir = $(DESTDIR)/usr/include
+includedir = $(prefix)/include
+localstatedir = $(prefix)/var
+sharedstatedir = $(prefix)/com
+sysconfdir = $(prefix)/etc
+datadir = $(datarootdir)
+datarootdir = $(prefix)/share
+libexecdir = $(exec_prefix)/libexec
+sbindir = $(exec_prefix)/sbin
+bindir = $(exec_prefix)/bin
+archdir = $(rubyarchdir)
+
+
+CC = gcc
+CXX = g++
+LIBRUBY = $(LIBRUBY_SO)
+LIBRUBY_A = lib$(RUBY_SO_NAME)-static.a
+LIBRUBYARG_SHARED = -Wl,-R$(libdir) -L$(libdir) -l$(RUBY_SO_NAME)
+LIBRUBYARG_STATIC = -Wl,-R$(libdir) -L$(libdir) -l$(RUBY_SO_NAME)-static
+empty =
+OUTFLAG = -o $(empty)
+COUTFLAG = -o $(empty)
+
+RUBY_EXTCONF_H = 
+cflags   =  $(optflags) $(debugflags) $(warnflags)
+optflags = -O3 -fno-fast-math
+debugflags = -ggdb3
+warnflags = -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wunused-variable -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration -Wdeprecated-declarations -Wno-packed-bitfield-compat
+CCDLFLAGS = -fPIC
+CFLAGS   = $(CCDLFLAGS) $(cflags)  -fPIC $(ARCH_FLAG)
+INCFLAGS = -I. -I$(arch_hdrdir) -I$(hdrdir) -I$(srcdir)
+DEFS     = 
+CPPFLAGS =   $(DEFS) $(cppflags)
+CXXFLAGS = $(CCDLFLAGS) $(cxxflags) $(ARCH_FLAG)
+ldflags  = -L. -fstack-protector -rdynamic -Wl,-export-dynamic
+dldflags =  
+ARCH_FLAG = 
+DLDFLAGS = $(ldflags) $(dldflags) $(ARCH_FLAG)
+LDSHARED = $(CC) -shared
+LDSHAREDXX = $(CXX) -shared
+AR = ar
+EXEEXT = 
+
+RUBY_INSTALL_NAME = $(RUBY_BASE_NAME)
+RUBY_SO_NAME = ruby
+RUBYW_INSTALL_NAME = 
+RUBY_VERSION_NAME = $(RUBY_BASE_NAME)-$(ruby_version)
+RUBYW_BASE_NAME = rubyw
+RUBY_BASE_NAME = ruby
+
+arch = x86_64-linux
+sitearch = $(arch)
+ruby_version = 2.2.0
+ruby = $(topdir)/miniruby -I'$(topdir)' -I'$(top_srcdir)/lib' -I'$(extout)/$(arch)' -I'$(extout)/common'
+RUBY = $(ruby)
+ruby_headers = $(hdrdir)/ruby.h $(hdrdir)/ruby/ruby.h $(hdrdir)/ruby/defines.h $(hdrdir)/ruby/missing.h $(hdrdir)/ruby/intern.h $(hdrdir)/ruby/st.h $(hdrdir)/ruby/subst.h $(arch_hdrdir)/ruby/config.h
+
+RM = rm -f
+RM_RF = $(RUBY) -run -e rm -- -rf
+RMDIRS = rmdir --ignore-fail-on-non-empty -p
+MAKEDIRS = /bin/mkdir -p
+INSTALL = /usr/bin/install -c
+INSTALL_PROG = $(INSTALL) -m 0755
+INSTALL_DATA = $(INSTALL) -m 644
+COPY = cp
+TOUCH = exit >
+
+#### End of system configuration section. ####
+
+preload = 
+CLEANFILES = mkmf.log
+DISTCLEANFILES = 
+
+all install static install-so install-rb: Makefile
+.PHONY: all install static install-so install-rb
+.PHONY: clean clean-so clean-static clean-rb
+
+
+clean-static::
+clean-rb-default::
+clean-rb::
+clean-so::
+clean: clean-so clean-static clean-rb-default clean-rb
+		-$(Q)$(RM) $(CLEANLIBS) $(CLEANOBJS) $(CLEANFILES) .*.time
+
+distclean-rb-default::
+distclean-rb::
+distclean-so::
+distclean-static::
+distclean: clean distclean-so distclean-static distclean-rb-default distclean-rb
+		-$(Q)$(RM) Makefile $(RUBY_EXTCONF_H) conftest.* mkmf.log
+		-$(Q)$(RM) core ruby$(EXEEXT) *~ $(DISTCLEANFILES)
+		-$(Q)$(RMDIRS) $(DISTCLEANDIRS) 2> /dev/null || true
+
+realclean: distclean
diff --git a/jni/ruby/ext/dbm/dbm.c b/jni/ruby/ext/dbm/dbm.c
new file mode 100644
index 0000000..41648b4
--- /dev/null
+++ b/jni/ruby/ext/dbm/dbm.c
@@ -0,0 +1,1159 @@
+/************************************************
+
+  dbm.c -
+
+  $Author: nobu $
+  created at: Mon Jan 24 15:59:52 JST 1994
+
+  Copyright (C) 1995-2001 Yukihiro Matsumoto
+
+************************************************/
+
+#include "ruby.h"
+
+#ifdef HAVE_CDEFS_H
+# include <cdefs.h>
+#endif
+#ifdef HAVE_SYS_CDEFS_H
+# include <sys/cdefs.h>
+#endif
+#include DBM_HDR
+#include <fcntl.h>
+#include <errno.h>
+
+#define DSIZE_TYPE TYPEOF_DATUM_DSIZE
+#if SIZEOF_DATUM_DSIZE > SIZEOF_INT
+# define RSTRING_DSIZE(s) RSTRING_LEN(s)
+# define TOO_LONG(n) 0
+#else
+# define RSTRING_DSIZE(s) RSTRING_LENINT(s)
+# define TOO_LONG(n) ((long)(+(DSIZE_TYPE)(n)) != (n))
+#endif
+
+static VALUE rb_cDBM, rb_eDBMError;
+
+#define RUBY_DBM_RW_BIT 0x20000000
+
+struct dbmdata {
+    long di_size;
+    DBM *di_dbm;
+};
+
+static void
+closed_dbm(void)
+{
+    rb_raise(rb_eDBMError, "closed DBM file");
+}
+
+#define GetDBM(obj, dbmp) do {\
+    TypedData_Get_Struct((obj), struct dbmdata, &dbm_type, (dbmp));\
+    if ((dbmp) == 0) closed_dbm();\
+    if ((dbmp)->di_dbm == 0) closed_dbm();\
+} while (0)
+
+#define GetDBM2(obj, dbmp, dbm) do {\
+    GetDBM((obj), (dbmp));\
+    (dbm) = (dbmp)->di_dbm;\
+} while (0)
+
+static void
+free_dbm(void *ptr)
+{
+    struct dbmdata *dbmp = ptr;
+    if (dbmp) {
+	if (dbmp->di_dbm) dbm_close(dbmp->di_dbm);
+	xfree(dbmp);
+    }
+}
+
+static size_t
+memsize_dbm(const void *ptr)
+{
+    size_t size = 0;
+    const struct dbmdata *dbmp = ptr;
+    if (dbmp) {
+	size += sizeof(*dbmp);
+	if (dbmp->di_dbm) size += DBM_SIZEOF_DBM;
+    }
+    return size;
+}
+
+static const rb_data_type_t dbm_type = {
+    "dbm",
+    {0, free_dbm, memsize_dbm,},
+    0, 0,
+    RUBY_TYPED_FREE_IMMEDIATELY,
+};
+
+/*
+ * call-seq:
+ *   dbm.close
+ *
+ * Closes the database.
+ */
+static VALUE
+fdbm_close(VALUE obj)
+{
+    struct dbmdata *dbmp;
+
+    GetDBM(obj, dbmp);
+    dbm_close(dbmp->di_dbm);
+    dbmp->di_dbm = 0;
+
+    return Qnil;
+}
+
+/*
+ * call-seq:
+ *   dbm.closed? -> true or false
+ *
+ * Returns true if the database is closed, false otherwise.
+ */
+static VALUE
+fdbm_closed(VALUE obj)
+{
+    struct dbmdata *dbmp;
+
+    TypedData_Get_Struct(obj, struct dbmdata, &dbm_type, dbmp);
+    if (dbmp == 0)
+	return Qtrue;
+    if (dbmp->di_dbm == 0)
+	return Qtrue;
+
+    return Qfalse;
+}
+
+static VALUE
+fdbm_alloc(VALUE klass)
+{
+    return TypedData_Wrap_Struct(klass, &dbm_type, 0);
+}
+
+/*
+ * call-seq:
+ *   DBM.new(filename[, mode[, flags]]) -> dbm
+ *
+ * Open a dbm database with the specified name, which can include a directory
+ * path. Any file extensions needed will be supplied automatically by the dbm
+ * library. For example, Berkeley DB appends '.db', and GNU gdbm uses two
+ * physical files with extensions '.dir' and '.pag'.
+ *
+ * The mode should be an integer, as for Unix chmod.
+ *
+ * Flags should be one of READER, WRITER, WRCREAT or NEWDB.
+ */
+static VALUE
+fdbm_initialize(int argc, VALUE *argv, VALUE obj)
+{
+    volatile VALUE file;
+    VALUE vmode, vflags;
+    DBM *dbm;
+    struct dbmdata *dbmp;
+    int mode, flags = 0;
+
+    if (rb_scan_args(argc, argv, "12", &file, &vmode, &vflags) == 1) {
+	mode = 0666;		/* default value */
+    }
+    else if (NIL_P(vmode)) {
+	mode = -1;		/* return nil if DB not exist */
+    }
+    else {
+	mode = NUM2INT(vmode);
+    }
+
+    if (!NIL_P(vflags))
+        flags = NUM2INT(vflags);
+
+    FilePathValue(file);
+
+    /*
+     * Note:
+     * gdbm 1.10 works with O_CLOEXEC.  gdbm 1.9.1 silently ignore it.
+     */
+#ifndef O_CLOEXEC
+#   define O_CLOEXEC 0
+#endif
+
+    if (flags & RUBY_DBM_RW_BIT) {
+        flags &= ~RUBY_DBM_RW_BIT;
+        dbm = dbm_open(RSTRING_PTR(file), flags|O_CLOEXEC, mode);
+    }
+    else {
+        dbm = 0;
+        if (mode >= 0) {
+            dbm = dbm_open(RSTRING_PTR(file), O_RDWR|O_CREAT|O_CLOEXEC, mode);
+        }
+        if (!dbm) {
+            dbm = dbm_open(RSTRING_PTR(file), O_RDWR|O_CLOEXEC, 0);
+        }
+        if (!dbm) {
+            dbm = dbm_open(RSTRING_PTR(file), O_RDONLY|O_CLOEXEC, 0);
+        }
+    }
+
+    if (dbm) {
+    /*
+     * History of dbm_pagfno() and dbm_dirfno() in ndbm and its compatibles.
+     * (dbm_pagfno() and dbm_dirfno() is not standardized.)
+     *
+     * 1986: 4.3BSD provides ndbm.
+     *       It provides dbm_pagfno() and dbm_dirfno() as macros.
+     * 1991: gdbm-1.5 provides them as functions.
+     *       They returns a same descriptor.
+     *       (Earlier releases may have the functions too.)
+     * 1991: Net/2 provides Berkeley DB.
+     *       It doesn't provide dbm_pagfno() and dbm_dirfno().
+     * 1992: 4.4BSD Alpha provides Berkeley DB with dbm_dirfno() as a function.
+     *       dbm_pagfno() is a macro as DBM_PAGFNO_NOT_AVAILABLE.
+     * 1997: Berkeley DB 2.0 is released by Sleepycat Software, Inc.
+     *       It defines dbm_pagfno() and dbm_dirfno() as macros.
+     * 2011: gdbm-1.9 creates a separate dir file.
+     *       dbm_pagfno() and dbm_dirfno() returns different descriptors.
+     */
+#if defined(HAVE_DBM_PAGFNO)
+        rb_fd_fix_cloexec(dbm_pagfno(dbm));
+#endif
+#if defined(HAVE_DBM_DIRFNO)
+        rb_fd_fix_cloexec(dbm_dirfno(dbm));
+#endif
+
+#if defined(RUBYDBM_DB_HEADER) && defined(HAVE_TYPE_DBC)
+    /* Disable Berkeley DB error messages such as:
+     * DB->put: attempt to modify a read-only database */
+        ((DBC*)dbm)->dbp->set_errfile(((DBC*)dbm)->dbp, NULL);
+#endif
+    }
+
+    if (!dbm) {
+	if (mode == -1) return Qnil;
+	rb_sys_fail_str(file);
+    }
+
+    dbmp = ALLOC(struct dbmdata);
+    DATA_PTR(obj) = dbmp;
+    dbmp->di_dbm = dbm;
+    dbmp->di_size = -1;
+
+    return obj;
+}
+
+/*
+ * call-seq:
+ *   DBM.open(filename[, mode[, flags]]) -> dbm
+ *   DBM.open(filename[, mode[, flags]]) {|dbm| block}
+ *
+ * Open a dbm database and yields it if a block is given. See also
+ * <code>DBM.new</code>.
+ */
+static VALUE
+fdbm_s_open(int argc, VALUE *argv, VALUE klass)
+{
+    VALUE obj = fdbm_alloc(klass);
+
+    if (NIL_P(fdbm_initialize(argc, argv, obj))) {
+	return Qnil;
+    }
+
+    if (rb_block_given_p()) {
+        return rb_ensure(rb_yield, obj, fdbm_close, obj);
+    }
+
+    return obj;
+}
+
+static VALUE
+fdbm_fetch(VALUE obj, VALUE keystr, VALUE ifnone)
+{
+    datum key, value;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+    long len;
+
+    ExportStringValue(keystr);
+    len = RSTRING_LEN(keystr);
+    if (TOO_LONG(len)) goto not_found;
+    key.dptr = RSTRING_PTR(keystr);
+    key.dsize = (DSIZE_TYPE)len;
+
+    GetDBM2(obj, dbmp, dbm);
+    value = dbm_fetch(dbm, key);
+    if (value.dptr == 0) {
+      not_found:
+	if (NIL_P(ifnone) && rb_block_given_p()) {
+	    keystr = rb_str_dup(keystr);
+	    OBJ_TAINT(keystr);
+	    return rb_yield(keystr);
+	}
+	return ifnone;
+    }
+    return rb_tainted_str_new(value.dptr, value.dsize);
+}
+
+/*
+ * call-seq:
+ *   dbm[key] -> string value or nil
+ *
+ * Return a value from the database by locating the key string
+ * provided.  If the key is not found, returns nil.
+ */
+static VALUE
+fdbm_aref(VALUE obj, VALUE keystr)
+{
+    return fdbm_fetch(obj, keystr, Qnil);
+}
+
+/*
+ * call-seq:
+ *   dbm.fetch(key[, ifnone]) -> value
+ *
+ * Return a value from the database by locating the key string
+ * provided.  If the key is not found, returns +ifnone+. If +ifnone+
+ * is not given, raises IndexError.
+ */
+static VALUE
+fdbm_fetch_m(int argc, VALUE *argv, VALUE obj)
+{
+    VALUE keystr, valstr, ifnone;
+
+    rb_scan_args(argc, argv, "11", &keystr, &ifnone);
+    valstr = fdbm_fetch(obj, keystr, ifnone);
+    if (argc == 1 && !rb_block_given_p() && NIL_P(valstr))
+	rb_raise(rb_eIndexError, "key not found");
+
+    return valstr;
+}
+
+/*
+ * call-seq:
+ *   dbm.key(value) -> string
+ *
+ * Returns the key for the specified value.
+ */
+static VALUE
+fdbm_key(VALUE obj, VALUE valstr)
+{
+    datum key, val;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+    long len;
+
+    ExportStringValue(valstr);
+    len = RSTRING_LEN(valstr);
+    if (TOO_LONG(len)) return Qnil;
+    val.dptr = RSTRING_PTR(valstr);
+    val.dsize = (DSIZE_TYPE)len;
+
+    GetDBM2(obj, dbmp, dbm);
+    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	val = dbm_fetch(dbm, key);
+	if ((long)val.dsize == RSTRING_LEN(valstr) &&
+	    memcmp(val.dptr, RSTRING_PTR(valstr), val.dsize) == 0) {
+	    return rb_tainted_str_new(key.dptr, key.dsize);
+	}
+    }
+    return Qnil;
+}
+
+/* :nodoc: */
+static VALUE
+fdbm_index(VALUE hash, VALUE value)
+{
+    rb_warn("DBM#index is deprecated; use DBM#key");
+    return fdbm_key(hash, value);
+}
+
+/*
+ * call-seq:
+ *   dbm.select {|key, value| block} -> array
+ *
+ * Returns a new array consisting of the [key, value] pairs for which the code
+ * block returns true.
+ */
+static VALUE
+fdbm_select(VALUE obj)
+{
+    VALUE new = rb_ary_new();
+    datum key, val;
+    DBM *dbm;
+    struct dbmdata *dbmp;
+
+    GetDBM2(obj, dbmp, dbm);
+    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	VALUE assoc, v;
+	val = dbm_fetch(dbm, key);
+	assoc = rb_assoc_new(rb_tainted_str_new(key.dptr, key.dsize),
+			     rb_tainted_str_new(val.dptr, val.dsize));
+	v = rb_yield(assoc);
+	if (RTEST(v)) {
+	    rb_ary_push(new, assoc);
+	}
+	GetDBM2(obj, dbmp, dbm);
+    }
+
+    return new;
+}
+
+/*
+ * call-seq:
+ *   dbm.values_at(key, ...) -> Array
+ *
+ * Returns an array containing the values associated with the given keys.
+ */
+static VALUE
+fdbm_values_at(int argc, VALUE *argv, VALUE obj)
+{
+    VALUE new = rb_ary_new2(argc);
+    int i;
+
+    for (i=0; i<argc; i++) {
+        rb_ary_push(new, fdbm_fetch(obj, argv[i], Qnil));
+    }
+
+    return new;
+}
+
+static void
+fdbm_modify(VALUE obj)
+{
+    if (OBJ_FROZEN(obj)) rb_error_frozen("DBM");
+}
+
+/*
+ * call-seq:
+ *   dbm.delete(key)
+ *
+ * Deletes an entry from the database.
+ */
+static VALUE
+fdbm_delete(VALUE obj, VALUE keystr)
+{
+    datum key, value;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+    VALUE valstr;
+    long len;
+
+    fdbm_modify(obj);
+    ExportStringValue(keystr);
+    len = RSTRING_LEN(keystr);
+    if (TOO_LONG(len)) goto not_found;
+    key.dptr = RSTRING_PTR(keystr);
+    key.dsize = (DSIZE_TYPE)len;
+
+    GetDBM2(obj, dbmp, dbm);
+
+    value = dbm_fetch(dbm, key);
+    if (value.dptr == 0) {
+      not_found:
+	if (rb_block_given_p()) return rb_yield(keystr);
+	return Qnil;
+    }
+
+    /* need to save value before dbm_delete() */
+    valstr = rb_tainted_str_new(value.dptr, value.dsize);
+
+    if (dbm_delete(dbm, key)) {
+	dbmp->di_size = -1;
+	rb_raise(rb_eDBMError, "dbm_delete failed");
+    }
+    else if (dbmp->di_size >= 0) {
+	dbmp->di_size--;
+    }
+    return valstr;
+}
+
+/*
+ * call-seq:
+ *   dbm.shift() -> [key, value]
+ *
+ * Removes a [key, value] pair from the database, and returns it.
+ * If the database is empty, returns nil.
+ * The order in which values are removed/returned is not guaranteed.
+ */
+static VALUE
+fdbm_shift(VALUE obj)
+{
+    datum key, val;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+    VALUE keystr, valstr;
+
+    fdbm_modify(obj);
+    GetDBM2(obj, dbmp, dbm);
+    dbmp->di_size = -1;
+
+    key = dbm_firstkey(dbm);
+    if (!key.dptr) return Qnil;
+    val = dbm_fetch(dbm, key);
+    keystr = rb_tainted_str_new(key.dptr, key.dsize);
+    valstr = rb_tainted_str_new(val.dptr, val.dsize);
+    dbm_delete(dbm, key);
+
+    return rb_assoc_new(keystr, valstr);
+}
+
+/*
+ * call-seq:
+ *   dbm.reject! {|key, value| block} -> self
+ *   dbm.delete_if {|key, value| block} -> self
+ *
+ * Deletes all entries for which the code block returns true.
+ * Returns self.
+ */
+static VALUE
+fdbm_delete_if(VALUE obj)
+{
+    datum key, val;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+    VALUE keystr, valstr;
+    VALUE ret, ary = rb_ary_tmp_new(0);
+    int i, status = 0;
+    long n;
+
+    fdbm_modify(obj);
+    GetDBM2(obj, dbmp, dbm);
+    n = dbmp->di_size;
+    dbmp->di_size = -1;
+
+    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	val = dbm_fetch(dbm, key);
+	keystr = rb_tainted_str_new(key.dptr, key.dsize);
+	OBJ_FREEZE(keystr);
+	valstr = rb_tainted_str_new(val.dptr, val.dsize);
+        ret = rb_protect(rb_yield, rb_assoc_new(rb_str_dup(keystr), valstr), &status);
+        if (status != 0) break;
+	if (RTEST(ret)) rb_ary_push(ary, keystr);
+	GetDBM2(obj, dbmp, dbm);
+    }
+
+    for (i = 0; i < RARRAY_LEN(ary); i++) {
+	keystr = RARRAY_PTR(ary)[i];
+	key.dptr = RSTRING_PTR(keystr);
+	key.dsize = (DSIZE_TYPE)RSTRING_LEN(keystr);
+	if (dbm_delete(dbm, key)) {
+	    rb_raise(rb_eDBMError, "dbm_delete failed");
+	}
+    }
+    if (status) rb_jump_tag(status);
+    if (n > 0) dbmp->di_size = n - RARRAY_LEN(ary);
+    rb_ary_clear(ary);
+
+    return obj;
+}
+
+/*
+ * call-seq:
+ *   dbm.clear
+ *
+ * Deletes all data from the database.
+ */
+static VALUE
+fdbm_clear(VALUE obj)
+{
+    datum key;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+
+    fdbm_modify(obj);
+    GetDBM2(obj, dbmp, dbm);
+    dbmp->di_size = -1;
+    while (key = dbm_firstkey(dbm), key.dptr) {
+	if (dbm_delete(dbm, key)) {
+	    rb_raise(rb_eDBMError, "dbm_delete failed");
+	}
+    }
+    dbmp->di_size = 0;
+
+    return obj;
+}
+
+/*
+ * call-seq:
+ *   dbm.invert -> hash
+ *
+ * Returns a Hash (not a DBM database) created by using each value in the
+ * database as a key, with the corresponding key as its value.
+ */
+static VALUE
+fdbm_invert(VALUE obj)
+{
+    datum key, val;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+    VALUE keystr, valstr;
+    VALUE hash = rb_hash_new();
+
+    GetDBM2(obj, dbmp, dbm);
+    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	val = dbm_fetch(dbm, key);
+	keystr = rb_tainted_str_new(key.dptr, key.dsize);
+	valstr = rb_tainted_str_new(val.dptr, val.dsize);
+	rb_hash_aset(hash, valstr, keystr);
+    }
+    return hash;
+}
+
+static VALUE fdbm_store(VALUE,VALUE,VALUE);
+
+static VALUE
+update_i(RB_BLOCK_CALL_FUNC_ARGLIST(pair, dbm))
+{
+    Check_Type(pair, T_ARRAY);
+    if (RARRAY_LEN(pair) < 2) {
+	rb_raise(rb_eArgError, "pair must be [key, value]");
+    }
+    fdbm_store(dbm, RARRAY_PTR(pair)[0], RARRAY_PTR(pair)[1]);
+    return Qnil;
+}
+
+/*
+ * call-seq:
+ *   dbm.update(obj)
+ *
+ * Updates the database with multiple values from the specified object.
+ * Takes any object which implements the each_pair method, including
+ * Hash and DBM objects.
+ */
+static VALUE
+fdbm_update(VALUE obj, VALUE other)
+{
+    rb_block_call(other, rb_intern("each_pair"), 0, 0, update_i, obj);
+    return obj;
+}
+
+/*
+ * call-seq:
+ *   dbm.replace(obj)
+ *
+ * Replaces the contents of the database with the contents of the specified
+ * object. Takes any object which implements the each_pair method, including
+ * Hash and DBM objects.
+ */
+static VALUE
+fdbm_replace(VALUE obj, VALUE other)
+{
+    fdbm_clear(obj);
+    rb_block_call(other, rb_intern("each_pair"), 0, 0, update_i, obj);
+    return obj;
+}
+
+/*
+ * call-seq:
+ *   dbm.store(key, value) -> value
+ *   dbm[key] = value
+ *
+ * Stores the specified string value in the database, indexed via the
+ * string key provided.
+ */
+static VALUE
+fdbm_store(VALUE obj, VALUE keystr, VALUE valstr)
+{
+    datum key, val;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+
+    fdbm_modify(obj);
+    keystr = rb_obj_as_string(keystr);
+    valstr = rb_obj_as_string(valstr);
+
+    key.dptr = RSTRING_PTR(keystr);
+    key.dsize = RSTRING_DSIZE(keystr);
+
+    val.dptr = RSTRING_PTR(valstr);
+    val.dsize = RSTRING_DSIZE(valstr);
+
+    GetDBM2(obj, dbmp, dbm);
+    dbmp->di_size = -1;
+    if (dbm_store(dbm, key, val, DBM_REPLACE)) {
+	dbm_clearerr(dbm);
+	if (errno == EPERM) rb_sys_fail(0);
+	rb_raise(rb_eDBMError, "dbm_store failed");
+    }
+
+    return valstr;
+}
+
+/*
+ * call-seq:
+ *   dbm.length -> integer
+ *   dbm.size -> integer
+ *
+ * Returns the number of entries in the database.
+ */
+static VALUE
+fdbm_length(VALUE obj)
+{
+    datum key;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+    int i = 0;
+
+    GetDBM2(obj, dbmp, dbm);
+    if (dbmp->di_size > 0) return INT2FIX(dbmp->di_size);
+
+    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	i++;
+    }
+    dbmp->di_size = i;
+
+    return INT2FIX(i);
+}
+
+/*
+ * call-seq:
+ *   dbm.empty?
+ *
+ * Returns true if the database is empty, false otherwise.
+ */
+static VALUE
+fdbm_empty_p(VALUE obj)
+{
+    datum key;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+
+    GetDBM2(obj, dbmp, dbm);
+    if (dbmp->di_size < 0) {
+	dbm = dbmp->di_dbm;
+
+	for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	    return Qfalse;
+	}
+    }
+    else {
+	if (dbmp->di_size)
+	    return Qfalse;
+    }
+    return Qtrue;
+}
+
+/*
+ * call-seq:
+ *   dbm.each_value {|value| block} -> self
+ *
+ * Calls the block once for each value string in the database. Returns self.
+ */
+static VALUE
+fdbm_each_value(VALUE obj)
+{
+    datum key, val;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+
+    RETURN_ENUMERATOR(obj, 0, 0);
+
+    GetDBM2(obj, dbmp, dbm);
+    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	val = dbm_fetch(dbm, key);
+	rb_yield(rb_tainted_str_new(val.dptr, val.dsize));
+	GetDBM2(obj, dbmp, dbm);
+    }
+    return obj;
+}
+
+/*
+ * call-seq:
+ *   dbm.each_key {|key| block} -> self
+ *
+ * Calls the block once for each key string in the database. Returns self.
+ */
+static VALUE
+fdbm_each_key(VALUE obj)
+{
+    datum key;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+
+    RETURN_ENUMERATOR(obj, 0, 0);
+
+    GetDBM2(obj, dbmp, dbm);
+    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	rb_yield(rb_tainted_str_new(key.dptr, key.dsize));
+	GetDBM2(obj, dbmp, dbm);
+    }
+    return obj;
+}
+
+/*
+ * call-seq:
+ *   dbm.each_pair {|key,value| block} -> self
+ *
+ * Calls the block once for each [key, value] pair in the database.
+ * Returns self.
+ */
+static VALUE
+fdbm_each_pair(VALUE obj)
+{
+    datum key, val;
+    DBM *dbm;
+    struct dbmdata *dbmp;
+    VALUE keystr, valstr;
+
+    RETURN_ENUMERATOR(obj, 0, 0);
+
+    GetDBM2(obj, dbmp, dbm);
+
+    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	val = dbm_fetch(dbm, key);
+	keystr = rb_tainted_str_new(key.dptr, key.dsize);
+	valstr = rb_tainted_str_new(val.dptr, val.dsize);
+	rb_yield(rb_assoc_new(keystr, valstr));
+	GetDBM2(obj, dbmp, dbm);
+    }
+
+    return obj;
+}
+
+/*
+ * call-seq:
+ *   dbm.keys -> array
+ *
+ * Returns an array of all the string keys in the database.
+ */
+static VALUE
+fdbm_keys(VALUE obj)
+{
+    datum key;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+    VALUE ary;
+
+    GetDBM2(obj, dbmp, dbm);
+
+    ary = rb_ary_new();
+    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	rb_ary_push(ary, rb_tainted_str_new(key.dptr, key.dsize));
+    }
+
+    return ary;
+}
+
+/*
+ * call-seq:
+ *   dbm.values -> array
+ *
+ * Returns an array of all the string values in the database.
+ */
+static VALUE
+fdbm_values(VALUE obj)
+{
+    datum key, val;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+    VALUE ary;
+
+    GetDBM2(obj, dbmp, dbm);
+    ary = rb_ary_new();
+    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	val = dbm_fetch(dbm, key);
+	rb_ary_push(ary, rb_tainted_str_new(val.dptr, val.dsize));
+    }
+
+    return ary;
+}
+
+/*
+ * call-seq:
+ *   dbm.include?(key) -> boolean
+ *   dbm.has_key?(key) -> boolean
+ *   dbm.member?(key) -> boolean
+ *   dbm.key?(key) -> boolean
+ *
+ * Returns true if the database contains the specified key, false otherwise.
+ */
+static VALUE
+fdbm_has_key(VALUE obj, VALUE keystr)
+{
+    datum key, val;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+    long len;
+
+    ExportStringValue(keystr);
+    len = RSTRING_LEN(keystr);
+    if (TOO_LONG(len)) return Qfalse;
+    key.dptr = RSTRING_PTR(keystr);
+    key.dsize = (DSIZE_TYPE)len;
+
+    GetDBM2(obj, dbmp, dbm);
+    val = dbm_fetch(dbm, key);
+    if (val.dptr) return Qtrue;
+    return Qfalse;
+}
+
+/*
+ * call-seq:
+ *   dbm.has_value?(value) -> boolean
+ *   dbm.value?(value) -> boolean
+ *
+ * Returns true if the database contains the specified string value, false
+ * otherwise.
+ */
+static VALUE
+fdbm_has_value(VALUE obj, VALUE valstr)
+{
+    datum key, val;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+    long len;
+
+    ExportStringValue(valstr);
+    len = RSTRING_LEN(valstr);
+    if (TOO_LONG(len)) return Qfalse;
+    val.dptr = RSTRING_PTR(valstr);
+    val.dsize = (DSIZE_TYPE)len;
+
+    GetDBM2(obj, dbmp, dbm);
+    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	val = dbm_fetch(dbm, key);
+	if ((DSIZE_TYPE)val.dsize == (DSIZE_TYPE)RSTRING_LEN(valstr) &&
+	    memcmp(val.dptr, RSTRING_PTR(valstr), val.dsize) == 0)
+	    return Qtrue;
+    }
+    return Qfalse;
+}
+
+/*
+ * call-seq:
+ *   dbm.to_a -> array
+ *
+ * Converts the contents of the database to an array of [key, value] arrays,
+ * and returns it.
+ */
+static VALUE
+fdbm_to_a(VALUE obj)
+{
+    datum key, val;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+    VALUE ary;
+
+    GetDBM2(obj, dbmp, dbm);
+    ary = rb_ary_new();
+    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	val = dbm_fetch(dbm, key);
+	rb_ary_push(ary, rb_assoc_new(rb_tainted_str_new(key.dptr, key.dsize),
+				      rb_tainted_str_new(val.dptr, val.dsize)));
+    }
+
+    return ary;
+}
+
+/*
+ * call-seq:
+ *   dbm.to_hash -> hash
+ *
+ * Converts the contents of the database to an in-memory Hash object, and
+ * returns it.
+ */
+static VALUE
+fdbm_to_hash(VALUE obj)
+{
+    datum key, val;
+    struct dbmdata *dbmp;
+    DBM *dbm;
+    VALUE hash;
+
+    GetDBM2(obj, dbmp, dbm);
+    hash = rb_hash_new();
+    for (key = dbm_firstkey(dbm); key.dptr; key = dbm_nextkey(dbm)) {
+	val = dbm_fetch(dbm, key);
+	rb_hash_aset(hash, rb_tainted_str_new(key.dptr, key.dsize),
+		           rb_tainted_str_new(val.dptr, val.dsize));
+    }
+
+    return hash;
+}
+
+/*
+ * call-seq:
+ *   dbm.reject {|key,value| block} -> Hash
+ *
+ * Converts the contents of the database to an in-memory Hash, then calls
+ * Hash#reject with the specified code block, returning a new Hash.
+ */
+static VALUE
+fdbm_reject(VALUE obj)
+{
+    return rb_hash_delete_if(fdbm_to_hash(obj));
+}
+
+/*
+ * == Introduction
+ *
+ * The DBM class provides a wrapper to a Unix-style
+ * {dbm}[http://en.wikipedia.org/wiki/Dbm] or Database Manager library.
+ *
+ * Dbm databases do not have tables or columns; they are simple key-value
+ * data stores, like a Ruby Hash except not resident in RAM. Keys and values
+ * must be strings.
+ *
+ * The exact library used depends on how Ruby was compiled. It could be any
+ * of the following:
+ *
+ * - The original ndbm library is released in 4.3BSD.
+ *   It is based on dbm library in Unix Version 7 but has different API to
+ *   support multiple databases in a process.
+ * - {Berkeley DB}[http://en.wikipedia.org/wiki/Berkeley_DB] versions
+ *   1 thru 5, also known as BDB and Sleepycat DB, now owned by Oracle
+ *   Corporation.
+ * - Berkeley DB 1.x, still found in 4.4BSD derivatives (FreeBSD, OpenBSD, etc).
+ * - {gdbm}[http://www.gnu.org/software/gdbm/], the GNU implementation of dbm.
+ * - {qdbm}[http://fallabs.com/qdbm/index.html], another open source
+ *   reimplementation of dbm.
+ *
+ * All of these dbm implementations have their own Ruby interfaces
+ * available, which provide richer (but varying) APIs.
+ *
+ * == Cautions
+ *
+ * Before you decide to use DBM, there are some issues you should consider:
+ *
+ * - Each implementation of dbm has its own file format. Generally, dbm
+ *   libraries will not read each other's files. This makes dbm files
+ *   a bad choice for data exchange.
+ *
+ * - Even running the same OS and the same dbm implementation, the database
+ *   file format may depend on the CPU architecture. For example, files may
+ *   not be portable between PowerPC and 386, or between 32 and 64 bit Linux.
+ *
+ * - Different versions of Berkeley DB use different file formats. A change to
+ *   the OS may therefore break DBM access to existing files.
+ *
+ * - Data size limits vary between implementations. Original Berkeley DB was
+ *   limited to 2GB of data. Dbm libraries also sometimes limit the total
+ *   size of a key/value pair, and the total size of all the keys that hash
+ *   to the same value. These limits can be as little as 512 bytes. That said,
+ *   gdbm and recent versions of Berkeley DB do away with these limits.
+ *
+ * Given the above cautions, DBM is not a good choice for long term storage of
+ * important data. It is probably best used as a fast and easy alternative
+ * to a Hash for processing large amounts of data.
+ *
+ * == Example
+ *
+ *  require 'dbm'
+ *  db = DBM.open('rfcs', 666, DBM::WRCREAT)
+ *  db['822'] = 'Standard for the Format of ARPA Internet Text Messages'
+ *  db['1123'] = 'Requirements for Internet Hosts - Application and Support'
+ *  db['3068'] = 'An Anycast Prefix for 6to4 Relay Routers'
+ *  puts db['822']
+ */
+void
+Init_dbm(void)
+{
+    rb_cDBM = rb_define_class("DBM", rb_cObject);
+    /* Document-class: DBMError
+     * Exception class used to return errors from the dbm library.
+     */
+    rb_eDBMError = rb_define_class("DBMError", rb_eStandardError);
+    rb_include_module(rb_cDBM, rb_mEnumerable);
+
+    rb_define_alloc_func(rb_cDBM, fdbm_alloc);
+    rb_define_singleton_method(rb_cDBM, "open", fdbm_s_open, -1);
+
+    rb_define_method(rb_cDBM, "initialize", fdbm_initialize, -1);
+    rb_define_method(rb_cDBM, "close", fdbm_close, 0);
+    rb_define_method(rb_cDBM, "closed?", fdbm_closed, 0);
+    rb_define_method(rb_cDBM, "[]", fdbm_aref, 1);
+    rb_define_method(rb_cDBM, "fetch", fdbm_fetch_m, -1);
+    rb_define_method(rb_cDBM, "[]=", fdbm_store, 2);
+    rb_define_method(rb_cDBM, "store", fdbm_store, 2);
+    rb_define_method(rb_cDBM, "index",  fdbm_index, 1);
+    rb_define_method(rb_cDBM, "key",  fdbm_key, 1);
+    rb_define_method(rb_cDBM, "select",  fdbm_select, 0);
+    rb_define_method(rb_cDBM, "values_at", fdbm_values_at, -1);
+    rb_define_method(rb_cDBM, "length", fdbm_length, 0);
+    rb_define_method(rb_cDBM, "size", fdbm_length, 0);
+    rb_define_method(rb_cDBM, "empty?", fdbm_empty_p, 0);
+    rb_define_method(rb_cDBM, "each", fdbm_each_pair, 0);
+    rb_define_method(rb_cDBM, "each_value", fdbm_each_value, 0);
+    rb_define_method(rb_cDBM, "each_key", fdbm_each_key, 0);
+    rb_define_method(rb_cDBM, "each_pair", fdbm_each_pair, 0);
+    rb_define_method(rb_cDBM, "keys", fdbm_keys, 0);
+    rb_define_method(rb_cDBM, "values", fdbm_values, 0);
+    rb_define_method(rb_cDBM, "shift", fdbm_shift, 0);
+    rb_define_method(rb_cDBM, "delete", fdbm_delete, 1);
+    rb_define_method(rb_cDBM, "delete_if", fdbm_delete_if, 0);
+    rb_define_method(rb_cDBM, "reject!", fdbm_delete_if, 0);
+    rb_define_method(rb_cDBM, "reject", fdbm_reject, 0);
+    rb_define_method(rb_cDBM, "clear", fdbm_clear, 0);
+    rb_define_method(rb_cDBM, "invert", fdbm_invert, 0);
+    rb_define_method(rb_cDBM, "update", fdbm_update, 1);
+    rb_define_method(rb_cDBM, "replace", fdbm_replace, 1);
+
+    rb_define_method(rb_cDBM, "include?", fdbm_has_key, 1);
+    rb_define_method(rb_cDBM, "has_key?", fdbm_has_key, 1);
+    rb_define_method(rb_cDBM, "member?", fdbm_has_key, 1);
+    rb_define_method(rb_cDBM, "has_value?", fdbm_has_value, 1);
+    rb_define_method(rb_cDBM, "key?", fdbm_has_key, 1);
+    rb_define_method(rb_cDBM, "value?", fdbm_has_value, 1);
+
+    rb_define_method(rb_cDBM, "to_a", fdbm_to_a, 0);
+    rb_define_method(rb_cDBM, "to_hash", fdbm_to_hash, 0);
+
+    /* Indicates that dbm_open() should open the database in read-only mode */
+    rb_define_const(rb_cDBM, "READER",  INT2FIX(O_RDONLY|RUBY_DBM_RW_BIT));
+
+    /* Indicates that dbm_open() should open the database in read/write mode */
+    rb_define_const(rb_cDBM, "WRITER",  INT2FIX(O_RDWR|RUBY_DBM_RW_BIT));
+
+    /* Indicates that dbm_open() should open the database in read/write mode,
+     * and create it if it does not already exist
+     */
+    rb_define_const(rb_cDBM, "WRCREAT", INT2FIX(O_RDWR|O_CREAT|RUBY_DBM_RW_BIT));
+
+    /* Indicates that dbm_open() should open the database in read/write mode,
+     * create it if it does not already exist, and delete all contents if it
+     * does already exist.
+     */
+    rb_define_const(rb_cDBM, "NEWDB",   INT2FIX(O_RDWR|O_CREAT|O_TRUNC|RUBY_DBM_RW_BIT));
+
+    {
+        VALUE version;
+#if defined(_DBM_IOERR)
+        version = rb_str_new2("ndbm (4.3BSD)");
+#elif defined(RUBYDBM_GDBM_HEADER)
+#  if defined(HAVE_DECLARED_LIBVAR_GDBM_VERSION)
+        /* since gdbm 1.9 */
+        version = rb_str_new2(gdbm_version);
+#  elif defined(HAVE_UNDECLARED_LIBVAR_GDBM_VERSION)
+        /* ndbm.h doesn't declare gdbm_version until gdbm 1.8.3.
+         * See extconf.rb for more information. */
+        RUBY_EXTERN char *gdbm_version;
+        version = rb_str_new2(gdbm_version);
+#  else
+        version = rb_str_new2("GDBM (unknown)");
+#  endif
+#elif defined(RUBYDBM_DB_HEADER)
+#  if defined(HAVE_DB_VERSION)
+        /* The version of the dbm library, if using Berkeley DB */
+        version = rb_str_new2(db_version(NULL, NULL, NULL));
+#  else
+        version = rb_str_new2("Berkeley DB (unknown)");
+#  endif
+#elif defined(_RELIC_H)
+#  if defined(HAVE_DPVERSION)
+        version = rb_sprintf("QDBM %s", dpversion);
+#  else
+        version = rb_str_new2("QDBM (unknown)");
+#  endif
+#else
+        version = rb_str_new2("ndbm (unknown)");
+#endif
+        /*
+         * Identifies ndbm library version.
+         *
+         * Examples:
+         *
+         * - "ndbm (4.3BSD)"
+         * - "Berkeley DB 4.8.30: (April  9, 2010)"
+         * - "Berkeley DB (unknown)" (4.4BSD, maybe)
+         * - "GDBM version 1.8.3. 10/15/2002 (built Jul  1 2011 12:32:45)"
+         * - "QDBM 1.8.78"
+         *
+         */
+        rb_define_const(rb_cDBM, "VERSION", version);
+    }
+}
diff --git a/jni/ruby/ext/dbm/extconf.rb b/jni/ruby/ext/dbm/extconf.rb
new file mode 100644
index 0000000..2c8caa3
--- /dev/null
+++ b/jni/ruby/ext/dbm/extconf.rb
@@ -0,0 +1,289 @@
+# configure option:
+#   --with-dbm-type=COMMA-SEPARATED-NDBM-TYPES
+#
+# ndbm type:
+#   libc        ndbm compatible library in libc.
+#   db          Berkeley DB (libdb)
+#   db2         Berkeley DB (libdb2)
+#   db1         Berkeley DB (libdb1)
+#   db5         Berkeley DB (libdb5)
+#   db4         Berkeley DB (libdb4)
+#   db3         Berkeley DB (libdb3)
+#   gdbm_compat GDBM since 1.8.1 (libgdbm_compat)
+#   gdbm        GDBM until 1.8.0 (libgdbm)
+#   qdbm        QDBM (libqdbm)
+#   ndbm        Some legacy OS may have libndbm.
+
+# :stopdoc:
+require 'mkmf'
+
+dir_config("dbm")
+
+if dblib = with_config("dbm-type", nil)
+  dblib = dblib.split(/[ ,]+/)
+else
+  dblib = %w(libc db db2 db1 db5 db4 db3 gdbm_compat gdbm qdbm)
+end
+
+headers = {
+  "libc" => ["ndbm.h"], # 4.3BSD original ndbm, Berkeley DB 1 in 4.4BSD libc.
+  "db" => ["db.h"],
+  "db1" => ["db1/ndbm.h", "db1.h", "ndbm.h"],
+  "db2" => ["db2/db.h", "db2.h", "db.h"],
+  "db3" => ["db3/db.h", "db3.h", "db.h"],
+  "db4" => ["db4/db.h", "db4.h", "db.h"],
+  "db5" => ["db5/db.h", "db5.h", "db.h"],
+  "gdbm_compat" => ["gdbm-ndbm.h", "gdbm/ndbm.h", "ndbm.h"], # GDBM since 1.8.1
+  "gdbm" => ["gdbm-ndbm.h", "gdbm/ndbm.h", "ndbm.h"], # GDBM until 1.8.0
+  "qdbm" => ["qdbm/relic.h", "relic.h"],
+}
+
+class << headers
+  attr_accessor :found
+  attr_accessor :defs
+end
+headers.found = []
+headers.defs = nil
+
+def headers.db_check(db, hdr)
+  old_libs = $libs.dup
+  old_defs = $defs.dup
+  result = db_check2(db, hdr)
+  if !result
+    $libs = old_libs
+    $defs = old_defs
+  end
+  result
+end
+
+def have_declared_libvar(var, headers = nil, opt = "", &b)
+  checking_for checking_message([*var].compact.join(' '), headers, opt) do
+    try_declared_libvar(var, headers, opt, &b)
+  end
+end
+
+def try_declared_libvar(var, headers = nil, opt = "", &b)
+  if try_link(<<"SRC", opt, &b)
+#{cpp_include(headers)}
+/*top*/
+int main(int argc, char *argv[]) {
+  void *conftest_var = &#{var};
+  return 0;
+}
+SRC
+    $defs.push(format("-DHAVE_DECLARED_LIBVAR_%s", var.tr_cpp))
+    true
+  else
+    false
+  end
+end
+
+def have_undeclared_libvar(var, headers = nil, opt = "", &b)
+  checking_for checking_message([*var].compact.join(' '), headers, opt) do
+    try_undeclared_libvar(var, headers, opt, &b)
+  end
+end
+
+def try_undeclared_libvar(var, headers = nil, opt = "", &b)
+  var, type = *var
+  if try_link(<<"SRC", opt, &b)
+#{cpp_include(headers)}
+/*top*/
+int main(int argc, char *argv[]) {
+  typedef #{type || 'int'} conftest_type;
+  extern conftest_type #{var};
+  conftest_type *conftest_var = &#{var};
+  return 0;
+}
+SRC
+    $defs.push(format("-DHAVE_UNDECLARED_LIBVAR_%s", var.tr_cpp))
+    true
+  else
+    false
+  end
+end
+
+def have_empty_macro_dbm_clearerr(headers = nil, opt = "", &b)
+  checking_for checking_message('empty macro of dbm_clearerr(foobarbaz)',
+                                headers, opt) do
+    try_toplevel('dbm_clearerr(foobarbaz)', headers, opt, &b)
+  end
+end
+
+def try_toplevel(src, headers = nil, opt = "", &b)
+  if try_compile(<<"SRC", opt, &b)
+#{cpp_include(headers)}
+/*top*/
+#{src}
+SRC
+    true
+  else
+    false
+  end
+end
+
+
+def headers.db_check2(db, hdr)
+  $defs.push(%{-DRUBYDBM_DBM_HEADER='"#{hdr}"'})
+  $defs.push(%{-DRUBYDBM_DBM_TYPE='"#{db}"'})
+
+  hsearch = nil
+
+  case db
+  when /^db[2-5]?$/
+    hsearch = "-DDB_DBM_HSEARCH"
+  when "gdbm_compat"
+    have_library("gdbm") or return false
+  end
+
+  if !have_type("DBM", hdr, hsearch)
+    return false
+  end
+
+  # 'libc' means ndbm is provided by libc.
+  # 4.3BSD original ndbm is contained in libc.
+  # 4.4BSD (and its derivatives such as NetBSD) contains Berkeley DB 1 in libc.
+  if !(db == 'libc' ? have_func('dbm_open("", 0, 0)', hdr, hsearch) :
+                      have_library(db, 'dbm_open("", 0, 0)', hdr, hsearch))
+    return false
+  end
+
+  # Skip a mismatch of Berkeley DB's ndbm.h and old GDBM library.
+  #
+  # dbm_clearerr() should be available for any ndbm implementation.
+  # It is available since the original (4.3BSD) ndbm and standardized by POSIX.
+  #
+  # However "can't resolve symbol 'dbm_clearerr'" problem may be caused by
+  # header/library mismatch: Berkeley DB ndbm.h and GDBM library until 1.8.3.
+  # GDBM (until 1.8.3) provides dbm_clearerr() as a empty macro in the header
+  # and the library don't provide dbm_clearerr().
+  # Berkeley DB provides dbm_clearerr() as a usual function.
+  # So Berkeley DB header with GDBM library causes the problem.
+  #
+  if !have_func('dbm_clearerr((DBM *)0)', hdr, hsearch)
+    return false
+  end
+
+  # Berkeley DB's ndbm.h (since 1.85 at least) defines DBM_SUFFIX.
+  # Note that _DB_H_ is not defined on Mac OS X because
+  # it uses Berkeley DB 1 but ndbm.h doesn't include db.h.
+  have_db_header = have_macro('DBM_SUFFIX', hdr, hsearch)
+
+  # Old GDBM's ndbm.h, until 1.8.3, defines dbm_clearerr as a macro which
+  # expands to no tokens.
+  have_gdbm_header1 = have_empty_macro_dbm_clearerr(hdr, hsearch)
+
+  # Recent GDBM's ndbm.h, since 1.9, includes gdbm.h and it defines _GDBM_H_.
+  # ndbm compatibility layer of GDBM is provided by libgdbm (until 1.8.0)
+  # and libgdbm_compat (since 1.8.1).
+  have_gdbm_header2 = have_macro('_GDBM_H_', hdr, hsearch)
+
+  # 4.3BSD's ndbm.h defines _DBM_IOERR.
+  # The original ndbm is provided by libc in 4.3BSD.
+  have_ndbm_header = have_macro('_DBM_IOERR', hdr, hsearch)
+
+  # GDBM provides ndbm functions in libgdbm_compat since GDBM 1.8.1.
+  # GDBM's ndbm.h defines _GDBM_H_ since GDBM 1.9.
+  # If _GDBM_H_ is defined, 'gdbm_compat' is required and reject 'gdbm'.
+  if have_gdbm_header2 && db == 'gdbm'
+    return false
+  end
+
+  if have_db_header
+    $defs.push('-DRUBYDBM_DB_HEADER')
+  end
+
+  have_gdbm_header = have_gdbm_header1 | have_gdbm_header2
+  if have_gdbm_header
+    $defs.push('-DRUBYDBM_GDBM_HEADER')
+  end
+
+  # ndbm.h is provided by the original (4.3BSD) ndbm,
+  # Berkeley DB 1 in libc of 4.4BSD and
+  # ndbm compatibility layer of GDBM.
+  # So, try to check header/library mismatch.
+  #
+  # Several (possibly historical) distributions provides libndbm.
+  # It may be Berkeley DB, GDBM or 4.3BSD ndbm.
+  # So mismatch check is not performed for that.
+  # Note that libndbm is searched only when --with-dbm-type=ndbm is
+  # given for configure.
+  #
+  if hdr == 'ndbm.h' && db != 'libc' && db != 'ndbm'
+    if /\Adb\d?\z/ !~ db && have_db_header
+      return false
+    end
+
+    if /\Agdbm/ !~ db && have_gdbm_header
+      return false
+    end
+
+    if have_ndbm_header
+      return false
+    end
+  end
+
+  # Berkeley DB
+  have_func('db_version((int *)0, (int *)0, (int *)0)', hdr, hsearch)
+
+  # GDBM
+  have_gdbm_version = have_declared_libvar("gdbm_version", hdr, hsearch)
+  # gdbm_version is available since very old version (GDBM 1.5 at least).
+  # However it is not declared by ndbm.h until GDBM 1.8.3.
+  # We can't include both ndbm.h and gdbm.h because they both define datum type.
+  # ndbm.h includes gdbm.h and gdbm_version is declared since GDBM 1.9.
+  have_gdbm_version |= have_undeclared_libvar(["gdbm_version", "char *"], hdr, hsearch)
+
+  # QDBM
+  have_var("dpversion", hdr, hsearch)
+
+  # detect mismatch between GDBM header and other library.
+  # If GDBM header is included, GDBM library should be linked.
+  if have_gdbm_header && !have_gdbm_version
+    return false
+  end
+
+  # DBC type is required to disable error messages by Berkeley DB 2 or later.
+  if have_db_header
+    have_type("DBC", hdr, hsearch)
+  end
+
+  if hsearch
+    $defs << hsearch
+    @defs = hsearch
+  end
+  $defs << '-DDBM_HDR="<'+hdr+'>"'
+  @found << hdr
+
+  puts "header: #{hdr}"
+  puts "library: #{db}"
+
+  true
+end
+
+if dblib.any? {|db| headers.fetch(db, ["ndbm.h"]).any? {|hdr| headers.db_check(db, hdr) } }
+  have_header("cdefs.h")
+  have_header("sys/cdefs.h")
+  have_func("dbm_pagfno((DBM *)0)", headers.found, headers.defs)
+  have_func("dbm_dirfno((DBM *)0)", headers.found, headers.defs)
+  convertible_int("datum.dsize", headers.found, headers.defs)
+  checking_for("sizeof(DBM) is available") {
+    if try_compile(<<SRC)
+#ifdef HAVE_CDEFS_H
+# include <cdefs.h>
+#endif
+#ifdef HAVE_SYS_CDEFS_H
+# include <sys/cdefs.h>
+#endif
+#include DBM_HDR
+
+const int sizeof_DBM = (int)sizeof(DBM);
+SRC
+      $defs << '-DDBM_SIZEOF_DBM=sizeof(DBM)'
+    else
+      $defs << '-DDBM_SIZEOF_DBM=0'
+    end
+  }
+  create_makefile("dbm")
+end
+# :startdoc: