mirror of https://github.com/python/cpython
88 lines
2.1 KiB
C
88 lines
2.1 KiB
C
#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;
|
|
}
|
|
|
|
// 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
|