Add initial implementation of idmap utilities

diff --git a/Makefile.am b/Makefile.am
index ddb9016..57f788c 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -198,7 +198,7 @@ src_ofonod_SOURCES = $(gdbus_sources) $(builtin_sources) \
                        src/phonebook.c src/history.c src/message-waiting.c \
                        src/simutil.h src/simutil.c src/storage.h \
                        src/storage.c src/cbs.c src/watch.c src/call-volume.c \
-                       src/gprs.c
+                       src/gprs.c src/idmap.h src/idmap.c
 
 src_ofonod_LDADD = $(builtin_libadd) @GLIB_LIBS@ @DBUS_LIBS@ -ldl
 

diff --git a/src/idmap.c b/src/idmap.c
new file mode 100644 (file)
index 0000000..f56c8e5
--- /dev/null
+++ b/src/idmap.c
@@ -0,0 +1,164 @@
+/*
+ *
+ *  oFono - Open Source Telephony
+ *
+ *  Copyright (C) 2008-2010  Intel Corporation. All rights reserved.
+ *  Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#define _GNU_SOURCE
+#include <string.h>
+
+#include <glib.h>
+
+#include "idmap.h"
+
+#define BITS_PER_LONG (sizeof(unsigned long) * 8)
+
+struct idmap {
+       unsigned long *bits;
+       unsigned int size;
+};
+
+static inline int ffz(unsigned long word)
+{
+       return __builtin_ctzl(~word);
+}
+
+/* 
+ * Stolen from linux kernel lib/find_next_bit.c
+ */
+static unsigned int find_next_zero_bit(const unsigned long *addr,
+                                       unsigned int size,
+                                       unsigned int offset)
+{
+       const unsigned long *p = addr + offset / BITS_PER_LONG;
+       unsigned int result = offset & ~(BITS_PER_LONG-1);
+       unsigned long tmp;
+
+       if (offset >= size)
+               return size;
+
+       size -= result;
+       offset %= BITS_PER_LONG;
+
+       if (offset) {
+               tmp = *(p++);
+               tmp |= ~0UL >> (BITS_PER_LONG - offset);
+
+               if (size < BITS_PER_LONG)
+                       goto found_first;
+
+               if (~tmp)
+                       goto found_middle;
+
+               size -= BITS_PER_LONG;
+               result += BITS_PER_LONG;
+       }
+
+       while (size & ~(BITS_PER_LONG-1)) {
+               if (~(tmp = *(p++)))
+                       goto found_middle;
+
+               size -= BITS_PER_LONG;
+               result += BITS_PER_LONG;
+       }
+
+       if (!size)
+               return result;
+
+       tmp = *p;
+
+found_first:
+       tmp |= ~0UL << size;
+
+       if (tmp == ~0UL)        /* Are any bits zero? */
+               return result + size;   /* Nope. */
+
+found_middle:
+       return result + ffz(tmp);
+}
+
+struct idmap *idmap_new(unsigned int size)
+{
+       struct idmap *ret = g_new0(struct idmap, 1);
+
+       ret->bits = g_new0(unsigned long,
+                               (size + BITS_PER_LONG - 1) / BITS_PER_LONG);
+       ret->size = size;
+
+       return ret;
+}
+
+void idmap_free(struct idmap *idmap)
+{
+       g_free(idmap->bits);
+       g_free(idmap);
+}
+
+void idmap_put(struct idmap *idmap, unsigned int bit)
+{
+       unsigned int offset = (bit - 1) / BITS_PER_LONG;
+
+       bit -= 1;
+
+       if (bit > idmap->size)
+               return;
+
+       bit %= BITS_PER_LONG;
+
+       idmap->bits[offset] &= ~(1 << bit);
+}
+
+unsigned int idmap_alloc(struct idmap *idmap)
+{
+       unsigned int bit;
+       unsigned int offset;
+
+       bit = find_next_zero_bit(idmap->bits, idmap->size, 0);
+
+       if (bit >= idmap->size)
+               return 0;
+
+       offset = bit / BITS_PER_LONG;
+       idmap->bits[offset] |= 1 << (bit % BITS_PER_LONG);
+
+       return bit + 1;
+}
+
+/*
+ * Allocate the next bit skipping the first last bits
+ */
+unsigned int idmap_alloc_next(struct idmap *idmap, unsigned int last)
+{
+       unsigned int bit;
+       unsigned int offset;
+
+       bit = find_next_zero_bit(idmap->bits, idmap->size, last);
+
+       if (bit >= idmap->size)
+               return idmap_alloc(idmap);
+
+       offset = bit / BITS_PER_LONG;
+       idmap->bits[offset] |= 1 << (bit % BITS_PER_LONG);
+
+       return bit + 1;
+}

diff --git a/src/idmap.h b/src/idmap.h
new file mode 100644 (file)
index 0000000..6f66ffc
--- /dev/null
+++ b/src/idmap.h
@@ -0,0 +1,28 @@
+/*
+ *
+ *  oFono - Open Source Telephony
+ *
+ *  Copyright (C) 2008-2010  Intel Corporation. All rights reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+struct idmap;
+
+struct idmap *idmap_new(unsigned int size);
+void idmap_free(struct idmap *idmap);
+void idmap_put(struct idmap *idmap, unsigned int bit);
+unsigned int idmap_alloc(struct idmap *idmap);
+unsigned int idmap_alloc_next(struct idmap *idmap, unsigned int last);