Add array utility functions

Makefile.in

@@ -38,7 +38,7 @@ DESTDIR=
 
 HASH_OBJ = @HASH_OBJ@
 
-OBJS = cmdparse.o conf.o local.o logging.o main.o memory.o mkdirpp.o \
+OBJS = array.o cmdparse.o conf.o local.o logging.o main.o memory.o mkdirpp.o \
        reference.o regress.o rtc.o sched.o sources.o sourcestats.o stubs.o \
        sys.o tempcomp.o util.o $(HASH_OBJ)
 

array.c

@@ -0,0 +1,121 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2014
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License 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 Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Functions implementing an array with automatic memory allocation.
+
+  */
+
+#include "config.h"
+
+#include "sysincl.h"
+
+#include "array.h"
+#include "memory.h"
+
+struct ARR_Instance_Record {
+  void *data;
+  unsigned int elem_size;
+  unsigned int used;
+  unsigned int allocated;
+};
+
+ARR_Instance
+ARR_CreateInstance(unsigned int elem_size)
+{
+  ARR_Instance array;
+
+  array = MallocNew(struct ARR_Instance_Record);
+
+  array->data = NULL;
+  array->elem_size = elem_size;
+  array->used = 0;
+  array->allocated = 0;
+
+  return array;
+}
+
+void
+ARR_DestroyInstance(ARR_Instance array)
+{
+  Free(array->data);
+  Free(array);
+}
+
+static void
+realloc_array(ARR_Instance array, unsigned int min_size)
+{
+  if (array->allocated >= min_size && array->allocated <= 2 * min_size)
+    return;
+
+  if (array->allocated < min_size) {
+    while (array->allocated < min_size)
+      array->allocated = array->allocated ? 2 * array->allocated : 1;
+  } else {
+    array->allocated = min_size;
+  }
+
+  array->data = Realloc(array->data, array->elem_size * array->allocated);
+}
+
+void *
+ARR_GetNewElement(ARR_Instance array)
+{
+  array->used++;
+  realloc_array(array, array->used);
+  return ARR_GetElement(array, array->used - 1);
+}
+
+void *
+ARR_GetElement(ARR_Instance array, unsigned int index)
+{
+  assert(index < array->used);
+  return (void *)((char *)array->data + index * array->elem_size);
+}
+
+void *
+ARR_GetElements(ARR_Instance array)
+{
+  return array->data;
+}
+
+void
+ARR_AppendElement(ARR_Instance array, void *element)
+{
+  void *e;
+
+  e = ARR_GetNewElement(array);
+  memcpy(e, element, array->elem_size);
+}
+
+void
+ARR_SetSize(ARR_Instance array, unsigned int size)
+{
+  realloc_array(array, size);
+  array->used = size;
+}
+
+unsigned int
+ARR_GetSize(ARR_Instance array)
+{
+  return array->used;
+}

array.h

@@ -0,0 +1,56 @@
+/*
+  chronyd/chronyc - Programs for keeping computer clocks accurate.
+
+ **********************************************************************
+ * Copyright (C) Miroslav Lichvar  2014
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License 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 Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * 
+ **********************************************************************
+
+  =======================================================================
+
+  Header file for array functions.
+  */
+
+#ifndef GOT_ARRAY_H
+#define GOT_ARRAY_H
+
+typedef struct ARR_Instance_Record *ARR_Instance;
+
+/* Create a new array with given element size */
+extern ARR_Instance ARR_CreateInstance(unsigned int elem_size);
+
+/* Destroy the array */
+extern void ARR_DestroyInstance(ARR_Instance array);
+
+/* Return pointer to a new element added to the end of the array */
+extern void *ARR_GetNewElement(ARR_Instance array);
+
+/* Return element with given index */
+extern void *ARR_GetElement(ARR_Instance array, unsigned int index);
+
+/* Return pointer to the internal array of elements */
+extern void *ARR_GetElements(ARR_Instance array);
+
+/* Add a new element to the end of the array */
+extern void ARR_AppendElement(ARR_Instance array, void *element);
+
+/* Set the size of the array */
+extern void ARR_SetSize(ARR_Instance array, unsigned int size);
+
+/* Return current size of the array */
+extern unsigned int ARR_GetSize(ARR_Instance array);
+
+#endif