Add heimbase

base/heimbase.c

@@ -0,0 +1,302 @@
+/*
+ * Copyright (c) 2010 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * All rights reserved.
+ *
+ * Portions Copyright (c) 2010 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "baselocl.h"
+
+static heim_base_atomic_type tidglobal = HEIM_TID_USER;
+
+struct heim_base {
+    heim_type_t isa;
+    heim_base_atomic_type ref_cnt;
+    uintptr_t isaextra[3]; 
+};
+
+/* specialized version of base */
+struct heim_base_mem {
+    heim_type_t isa;
+    heim_base_atomic_type ref_cnt;
+    const char *name;
+    void (*dealloc)(void *);
+    uintptr_t isaextra[1]; 
+};
+
+#define PTR2BASE(ptr) (((struct heim_base *)ptr) - 1)
+#define BASE2PTR(ptr) ((void *)(((struct heim_base *)ptr) + 1))
+
+/**
+ * Retain object
+ *
+ * @param object to be released, NULL is ok
+ *
+ * @return the same object as passed in
+ */
+
+void *
+heim_retain(void *ptr)
+{
+    struct heim_base *p = PTR2BASE(ptr);
+
+    if (ptr == NULL || heim_base_is_tagged(ptr))
+	return ptr;
+
+    if (p->ref_cnt == heim_base_atomic_max)
+	return ptr;
+
+    if ((heim_base_atomic_inc(&p->ref_cnt) - 1) == 0)
+	HEIM_BASE_ABORT("resurection");
+    return ptr;
+}
+
+/**
+ * Release object, free is reference count reaches zero
+ *
+ * @param object to be released
+ */
+
+void
+heim_release(void *ptr)
+{
+    heim_base_atomic_type old;
+    struct heim_base *p = PTR2BASE(ptr);
+
+    if (ptr == NULL || heim_base_is_tagged(ptr))
+	return;
+
+    if (p->ref_cnt == heim_base_atomic_max)
+	return;
+
+    old = heim_base_atomic_dec(&p->ref_cnt) + 1;
+
+    if (old > 1)
+	return;
+
+    if (old == 1) {
+	if (p->isa->dealloc)
+	    p->isa->dealloc(ptr);
+	free(p);
+    } else
+	HEIM_BASE_ABORT("over release");
+}
+
+static heim_type_t tagged_isa[9] = {
+    &_heim_number_object,
+    &_heim_null_object,
+    &_heim_bool_object,
+
+    NULL,
+    NULL,
+    NULL,
+
+    NULL,
+    NULL,
+    NULL
+};
+
+heim_type_t
+_heim_get_isa(heim_object_t ptr)
+{
+    struct heim_base *p;
+    if (heim_base_is_tagged(ptr)) {
+	if (heim_base_is_tagged_object(ptr))
+	    return tagged_isa[heim_base_tagged_object_tid(ptr)];
+	if (heim_base_is_tagged_string(ptr))
+	    return &_heim_string_object;
+	abort();
+    }
+    p = PTR2BASE(ptr);
+    return p->isa;
+}
+
+/**
+ * Get type ID of object
+ *
+ * @param object object to get type id of
+ *
+ * @return type id of object
+ */
+
+heim_tid_t
+heim_get_tid(heim_object_t ptr)
+{
+    heim_type_t isa = _heim_get_isa(ptr);
+    return isa->tid;
+}
+
+/**
+ * Get hash value of object
+ *
+ * @param object object to get hash value for
+ *
+ * @return a hash value
+ */
+
+unsigned long
+heim_get_hash(heim_object_t ptr)
+{
+    heim_type_t isa = _heim_get_isa(ptr);
+    if (isa->hash)
+	return isa->hash(ptr);
+    return (unsigned long)ptr;
+}
+
+/**
+ * Compare two objects, returns 0 if equal, can use used for qsort()
+ * and friends.
+ *
+ * @param a first object to compare
+ * @param b first object to compare
+ *
+ * @return 0 if objects are equal
+ */
+
+int
+heim_cmp(heim_object_t a, heim_object_t b)
+{
+    heim_tid_t ta, tb;
+    heim_type_t isa;
+ 
+    ta = heim_get_tid(a);
+    tb = heim_get_tid(b);
+
+    if (ta != tb)
+	return ta - tb;
+
+    isa = _heim_get_isa(a);
+
+    if (isa->cmp)
+	return isa->cmp(a, b);
+
+    return (uintptr_t)a - (uintptr_t)b;
+}
+
+/*
+ * Private - allocates an memory object
+ */
+
+static void
+memory_dealloc(void *ptr)
+{
+    struct heim_base_mem *p = (struct heim_base_mem *)PTR2BASE(ptr);
+    if (p->dealloc)
+	p->dealloc(ptr);
+}
+
+struct heim_type_data memory_object = {
+    HEIM_TID_MEMORY,
+    "memory-object",
+    NULL,
+    memory_dealloc,
+    NULL,
+    NULL,
+    NULL
+};
+
+void *
+heim_alloc(size_t size, const char *name, heim_type_dealloc dealloc)
+{
+    /* XXX use posix_memalign */
+
+    struct heim_base_mem *p = calloc(1, size + sizeof(*p));
+    if (p == NULL)
+	return NULL;
+    p->isa = &memory_object;
+    p->ref_cnt = 1;
+    p->name = name;
+    p->dealloc = dealloc;
+    return BASE2PTR(p);
+}
+
+heim_type_t
+_heim_create_type(const char *name,
+		  heim_type_init init,
+		  heim_type_dealloc dealloc,
+		  heim_type_copy copy,
+		  heim_type_cmp cmp,
+		  heim_type_hash hash)
+{
+    heim_type_t type;
+
+    /* XXX posix_memalign */
+
+    type = calloc(1, sizeof(*type));
+    if (type == NULL)
+	return NULL;
+
+    type->tid = heim_base_atomic_inc(&tidglobal);
+    type->name = name;
+    type->init = init;
+    type->dealloc = dealloc;
+    type->copy = copy;
+    type->cmp = cmp;
+    type->hash = hash;
+
+    return type;
+}
+
+heim_object_t
+_heim_alloc_object(heim_type_t type, size_t size)
+{
+    struct heim_base *p = calloc(1, size + sizeof(*p));
+    if (p == NULL)
+	return NULL;
+    p->isa = type;
+    p->ref_cnt = 1;
+
+    return BASE2PTR(p);
+}
+
+heim_tid_t
+_heim_type_get_tid(heim_type_t type)
+{
+    return type->tid;
+}
+
+/**
+ * Call func once and only once
+ *
+ * @param once pointer to a heim_base_once_t
+ * @param ctx context passed to func
+ * @param func function to be called
+ */
+
+void
+heim_base_once_f(heim_base_once_t *once, void *ctx, void (*func)(void *))
+{
+#ifdef HAVE_DISPATCH_DISPATCH_H
+    dispatch_once_f(once, ctx, func);
+#else
+    #error "write heim_base_once_t"
+#endif
+}