src/data_internal.h

   1 /*
   2  * Copyright (c) 2009-2012 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_APACHE_LICENSE_HEADER_START@
   5  *
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  *
  18  * @APPLE_APACHE_LICENSE_HEADER_END@
  19  */
  20
  21 /*
  22  * IMPORTANT: This header file describes INTERNAL interfaces to libdispatch
  23  * which are subject to change in future releases of Mac OS X. Any applications
  24  * relying on these interfaces WILL break.
  25  */
  26
  27 #ifndef __DISPATCH_DATA_INTERNAL__
  28 #define __DISPATCH_DATA_INTERNAL__
  29
  30 #ifndef __DISPATCH_INDIRECT__
  31 #error "Please #include <dispatch/dispatch.h> instead of this file directly."
  32 #include <dispatch/base.h> // for HeaderDoc
  33 #endif
  34
  35 #if defined(__LP64__) && !defined(DISPATCH_DATA_USE_LEAF_MEMBER) && !USE_OBJC
  36 // explicit leaf member is free on 64bit due to padding
  37 #define DISPATCH_DATA_USE_LEAF_MEMBER 1
  38 #endif
  39
  40 typedef struct range_record_s {
  41         dispatch_data_t data_object;
  42         size_t from;
  43         size_t length;
  44 } range_record;
  45
  46 #if USE_OBJC
  47 #if OS_OBJECT_USE_OBJC
  48 @interface DISPATCH_CLASS(data) : NSObject <DISPATCH_CLASS(data)>
  49 @end
  50 #endif
  51 DISPATCH_OBJC_CLASS_DECL(data);
  52 DISPATCH_OBJC_CLASS_DECL(data_empty);
  53 #define DISPATCH_DATA_CLASS DISPATCH_OBJC_CLASS(data)
  54 #define DISPATCH_DATA_EMPTY_CLASS DISPATCH_OBJC_CLASS(data_empty)
  55 #else // USE_OBJC
  56 DISPATCH_CLASS_DECL(data);
  57 #define DISPATCH_DATA_CLASS DISPATCH_VTABLE(data)
  58 #define DISPATCH_DATA_EMPTY_CLASS DISPATCH_VTABLE(data)
  59 #endif // USE_OBJC
  60
  61 struct dispatch_data_s {
  62 #if USE_OBJC
  63         const void *do_vtable;
  64         dispatch_queue_t do_targetq;
  65         void *ctxt;
  66         void *finalizer;
  67 #else // USE_OBJC
  68         DISPATCH_STRUCT_HEADER(data);
  69 #endif // USE_OBJC
  70 #if DISPATCH_DATA_USE_LEAF_MEMBER
  71         bool leaf;
  72 #endif
  73         dispatch_block_t destructor;
  74         size_t size, num_records;
  75         union {
  76                 const void* buf;
  77                 range_record records[0];
  78         };
  79 };
  80
  81 #if DISPATCH_DATA_USE_LEAF_MEMBER
  82 #define _dispatch_data_leaf(d) ((d)->leaf)
  83 #define _dispatch_data_num_records(d) ((d)->num_records)
  84 #else
  85 #define _dispatch_data_leaf(d) ((d)->num_records ? 0 : ((d)->size ? 1 : 0))
  86 #define _dispatch_data_num_records(d) \
  87                 (_dispatch_data_leaf(d) ? 1 : (d)->num_records)
  88 #endif // DISPATCH_DATA_USE_LEAF_MEMBER
  89
  90 typedef dispatch_data_t (*dispatch_transform_t)(dispatch_data_t data);
  91
  92 struct dispatch_data_format_type_s {
  93         uint64_t type;
  94         uint64_t input_mask;
  95         uint64_t output_mask;
  96         dispatch_transform_t decode;
  97         dispatch_transform_t encode;
  98 };
  99
 100 void dispatch_data_init(dispatch_data_t data, const void *buffer, size_t size,
 101                 dispatch_block_t destructor);
 102 void _dispatch_data_dispose(dispatch_data_t data);
 103 size_t _dispatch_data_debug(dispatch_data_t data, char* buf, size_t bufsiz);
 104 const dispatch_block_t _dispatch_data_destructor_inline;
 105 #define DISPATCH_DATA_DESTRUCTOR_INLINE (_dispatch_data_destructor_inline)
 106
 107 #if !__OBJC2__
 108
 109 static inline const void*
 110 _dispatch_data_map_direct(dispatch_data_t dd)
 111 {
 112         size_t offset = 0;
 113         if (slowpath(!dd->size)) {
 114                 return NULL;
 115         }
 116         if (slowpath(!_dispatch_data_leaf(dd)) &&
 117                         _dispatch_data_num_records(dd) == 1 &&
 118                         _dispatch_data_leaf(dd->records[0].data_object)) {
 119                 offset = dd->records[0].from;
 120                 dd = dd->records[0].data_object;
 121         }
 122         return fastpath(_dispatch_data_leaf(dd)) ? (dd->buf + offset) : NULL;
 123 }
 124
 125 #endif // !__OBJC2__
 126
 127 #endif // __DISPATCH_DATA_INTERNAL__