Repository navigation
Expand file tree
/
Copy pathpycore_object_stack.h
More file actions
97 lines (80 loc) · 2.33 KB
/
Copy pathpycore_object_stack.h
File metadata and controls
97 lines (80 loc) · 2.33 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
#ifndef Py_INTERNAL_OBJECT_STACK_H
#define Py_INTERNAL_OBJECT_STACK_H
#include "pycore_freelist.h" // _PyFreeListState
#ifdef __cplusplus
extern "C" {
#endif
#ifndef Py_BUILD_CORE
# error "this header requires Py_BUILD_CORE define"
#endif
// _PyObjectStack is a stack of Python objects implemented as a linked list of
// fixed size buffers.
// Chosen so that _PyObjectStackChunk is a power-of-two size.
#define _Py_OBJECT_STACK_CHUNK_SIZE 254
typedef struct _PyObjectStackChunk {
struct _PyObjectStackChunk *prev;
Py_ssize_t n;
PyObject *objs[_Py_OBJECT_STACK_CHUNK_SIZE];
} _PyObjectStackChunk;
typedef struct _PyObjectStack {
_PyObjectStackChunk *head;
} _PyObjectStack;
extern _PyObjectStackChunk *
_PyObjectStackChunk_New(void);
extern void
_PyObjectStackChunk_Free(_PyObjectStackChunk *);
// Push an item onto the stack. Return -1 on allocation failure, 0 on success.
static inline int
_PyObjectStack_Push(_PyObjectStack *stack, PyObject *obj)
{
_PyObjectStackChunk *buf = stack->head;
if (buf == NULL || buf->n == _Py_OBJECT_STACK_CHUNK_SIZE) {
buf = _PyObjectStackChunk_New();
if (buf == NULL) {
return -1;
}
buf->prev = stack->head;
buf->n = 0;
stack->head = buf;
}
assert(buf->n >= 0 && buf->n < _Py_OBJECT_STACK_CHUNK_SIZE);
buf->objs[buf->n] = obj;
buf->n++;
return 0;
}
// Pop the top item from the stack. Return NULL if the stack is empty.
static inline PyObject *
_PyObjectStack_Pop(_PyObjectStack *stack)
{
_PyObjectStackChunk *buf = stack->head;
if (buf == NULL) {
return NULL;
}
assert(buf->n > 0 && buf->n <= _Py_OBJECT_STACK_CHUNK_SIZE);
buf->n--;
PyObject *obj = buf->objs[buf->n];
if (buf->n == 0) {
stack->head = buf->prev;
_PyObjectStackChunk_Free(buf);
}
return obj;
}
static inline Py_ssize_t
_PyObjectStack_Size(_PyObjectStack *stack)
{
Py_ssize_t size = 0;
for (_PyObjectStackChunk *buf = stack->head; buf != NULL; buf = buf->prev) {
size += buf->n;
}
return size;
}
// Merge src into dst, leaving src empty
extern void
_PyObjectStack_Merge(_PyObjectStack *dst, _PyObjectStack *src);
// Remove all items from the stack
extern void
_PyObjectStack_Clear(_PyObjectStack *stack);
#ifdef __cplusplus
}
#endif
#endif // !Py_INTERNAL_OBJECT_STACK_H