addons/SkipDB/source/IoSkipDBCursor.c

   1
   2 //metadoc SkipDBCursor copyright Steve Dekorte 2002
   3 //metadoc SkipDBCursor license BSD revised
   4 //metadoc SkipDBCursor category Databases")
   5 /*metadoc description
   6 An interator object for a SkipDB.
   7 */
   8
   9 #include "IoSkipDBCursor.h"
  10 #include "SkipDB.h"
  11 #include "IoObject.h"
  12 #include "IoState.h"
  13 #include "IoSeq.h"
  14 #include "IoState.h"
  15 #include "IoNumber.h"
  16
  17 #define CURSOR(self) ((SkipDBCursor *)(IoObject_dataPointer(self)))
  18
  19 IoTag *IoSkipDBCursor_newTag(void *state)
  20 {
  21         IoTag *tag = IoTag_newWithName_("SkipDBCursor");
  22         IoTag_state_(tag, state);
  23         IoTag_freeFunc_(tag, (IoTagFreeFunc *)IoSkipDBCursor_free);
  24         IoTag_cloneFunc_(tag, (IoTagCloneFunc *)IoSkipDBCursor_rawClone);
  25         //IoTag_markFunc_(tag, (IoTagMarkFunc *)IoSkipDBCursor_mark);
  26         //IoTag_writeToStreamFunc_(tag, (IoTagWriteToStoreOnStreamFunc *)IoSkipDBCursor_writeToStore_stream_);
  27         //IoTag_readFromStreamFunc_(tag, (IoTagReadFromStoreOnStreamFunc *)IoSkipDBCursor_readFromStore_stream_);
  28         return tag;
  29 }
  30
  31 /*
  32 void IoSkipDBCursor_writeToStream_(IoObject *self, BStream *stream)
  33 {
  34 }
  35
  36 void IoSkipDBCursor_readFromStream_(IoObject *self, BStream *stream)
  37 {
  38 }
  39 */
  40
  41 IoSkipDBCursor *IoSkipDBCursor_proto(void *state)
  42 {
  43         IoMethodTable methodTable[] = {
  44         {"goto",     IoSkipDBCursor_goto},
  45         {"first",    IoSkipDBCursor_first},
  46         {"last",     IoSkipDBCursor_last},
  47         {"next",     IoSkipDBCursor_next},
  48         {"previous", IoSkipDBCursor_previous},
  49         {"key",  IoSkipDBCursor_key},
  50         {"value",  IoSkipDBCursor_value},
  51         {NULL, NULL},
  52         };
  53
  54         IoObject *self = IoObject_new(state);
  55         IoObject_tag_(self, IoSkipDBCursor_newTag(state));
  56
  57         IoObject_setDataPointer_(self, NULL);
  58         IoState_registerProtoWithFunc_((IoState *)state, self, IoSkipDBCursor_proto);
  59
  60         IoObject_addMethodTable_(self, methodTable);
  61         return self;
  62 }
  63
  64 IoSkipDBCursor *IoSkipDBCursor_rawClone(IoSkipDBCursor *proto)
  65 {
  66         IoObject *self = IoObject_rawClonePrimitive(proto);
  67         IoObject_tag_(self, IoObject_tag(proto));
  68         IoObject_setDataPointer_(self, NULL);
  69         return self;
  70 }
  71
  72 IoSkipDBCursor *IoSkipDBCursor_new(void *state)
  73 {
  74         IoObject *proto = IoState_protoWithInitFunction_((IoState *)state, IoSkipDBCursor_proto);
  75         return IOCLONE(proto);
  76 }
  77
  78 IoSkipDBCursor *IoSkipDBCursor_newWithSDBCursor(void *state, SkipDBCursor *cursor)
  79 {
  80         IoSkipDBCursor *self = IoSkipDBCursor_new(state);
  81         SkipDBCursor_retain(cursor);
  82         IoObject_setDataPointer_(self, cursor);
  83         return self;
  84 }
  85
  86 void IoSkipDBCursor_free(IoSkipDBCursor *self)
  87 {
  88         if (CURSOR(self)) SkipDBCursor_release(CURSOR(self));
  89 }
  90
  91 /*
  92 void IoSkipDBCursor_mark(IoSkipDBCursor *self)
  93 {
  94 }
  95 */
  96
  97 // --------------------------------------------------------
  98
  99 IoObject *IoSkipDBCursor_goto(IoObject *self, IoObject *locals, IoMessage *m)
 100 {
 101         /*doc SkipDBCursor goto(aKey)
 102         Move cursor to the specified key or nearest preceeding key. Returns self
 103         */
 104
 105         IoSeq *key = IoMessage_locals_seqArgAt_(m, locals, 0);
 106         IOASSERT(CURSOR(self), "SkipDBCursor invalid");
 107         SkipDBCursor_goto_(CURSOR(self), IoSeq_asDatum(key));
 108         return self;
 109 }
 110
 111 IoObject *IoSkipDBCursor_first(IoObject *self, IoObject *locals, IoMessage *m)
 112 {
 113         /*doc SkipDBCursor first
 114         Move cursor to first item. Returns self.
 115         */
 116
 117         IOASSERT(CURSOR(self), "SkipDBCursor invalid");
 118         SkipDBCursor_first(CURSOR(self));
 119         return self;
 120 }
 121
 122 IoObject *IoSkipDBCursor_last(IoObject *self, IoObject *locals, IoMessage *m)
 123 {
 124         /*doc SkipDBCursor last
 125         Move cursor to last item. Returns self.
 126         */
 127
 128         IOASSERT(CURSOR(self), "SkipDBCursor invalid");
 129         SkipDBCursor_last(CURSOR(self));
 130         return self;
 131 }
 132
 133 IoObject *IoSkipDBCursor_next(IoObject *self, IoObject *locals, IoMessage *m)
 134 {
 135         /*doc SkipDBCursor next
 136         Move cursor to next item. Returns self.
 137         */
 138
 139         IOASSERT(CURSOR(self), "SkipDBCursor invalid");
 140         SkipDBCursor_next(CURSOR(self));
 141         return self;
 142 }
 143
 144 IoObject *IoSkipDBCursor_previous(IoObject *self, IoObject *locals, IoMessage *m)
 145 {
 146         /*doc SkipDBCursor previous
 147         Move cursor to previous item. Returns self.
 148         */
 149
 150         IOASSERT(CURSOR(self), "SkipDBCursor invalid");
 151         SkipDBCursor_previous(CURSOR(self));
 152         return self;
 153 }
 154
 155 IoObject *IoSkipDBCursor_key(IoObject *self, IoObject *locals, IoMessage *m)
 156 {
 157         /*doc SkipDBCursor key
 158         Returns the current cursor key, or nil if the cursor is out of range.
 159         */
 160
 161         IOASSERT(CURSOR(self), "SkipDBCursor invalid");
 162
 163         {
 164         SkipDBRecord *r = SkipDBCursor_current(CURSOR(self));
 165
 166         if (r)
 167         {
 168                 Datum k = SkipDBRecord_keyDatum(r);
 169                 return IoSeq_newWithDatum_(IOSTATE, &k);
 170         }
 171
 172         return IONIL(self);
 173         }
 174 }
 175
 176 IoObject *IoSkipDBCursor_value(IoObject *self, IoObject *locals, IoMessage *m)
 177 {
 178         /*doc SkipDBCursor value
 179         Returns the current cursor key, or nil if the cursor is out of range.
 180         */
 181
 182         IOASSERT(CURSOR(self), "SkipDBCursor invalid");
 183
 184         {
 185         SkipDBRecord *r = SkipDBCursor_current(CURSOR(self));
 186
 187         if (r)
 188         {
 189                 Datum v = SkipDBRecord_valueDatum(r);
 190                 return IoSeq_newWithDatum_(IOSTATE, &v);
 191         }
 192
 193         return IONIL(self);
 194         }
 195 }
 196