##// END OF EJS Templates
demandimport: replace more references to _demandmod instances...
demandimport: replace more references to _demandmod instances _demandmod instances may be referenced by multiple importing modules. Before this patch, the _demandmod instance only maintained a reference to its first consumer when using the "from X import Y" syntax. This is because we only created a single _demandmod instance (attached to the parent X module). If multiple modules A and B performed "from X import Y", we'd produce a single _demandmod instance "demandmod" with the following references: X.Y = <demandmod> A.Y = <demandmod> B.Y = <demandmod> The locals from the first consumer (A) would be stored in <demandmod1>. When <demandmod1> was loaded, we'd look at the locals for the first consumer and replace the symbol, if necessary. This resulted in state: X.Y = <module> A.Y = <module> B.Y = <demandmod> B's reference to Y wasn't updated and was still using the proxy object because we just didn't record that B had a reference to <demandmod> that needed updating! With this patch, we add support for tracking which modules in addition to the initial importer have a reference to the _demandmod instance and we replace those references at module load time. In the case of posix.py, this fixes an issue where the "encoding" module was being proxied, resulting in hundreds of thousands of __getattribute__ lookups on the _demandmod instance during dirstate operations on mozilla-central, speeding up execution by many milliseconds. There are likely several other operation that benefit from this change as well. The new mechanism isn't perfect: references in locals (not globals) may likely linger. So, if there is an import inside a function and a symbol from that module is used in a hot loop, we could have unwanted overhead from proxying through _demandmod. Non-global imports are discouraged anyway. So hopefully this isn't a big deal in practice. We could potentially deploy a code checker that bans use of attribute lookups of function-level-imported modules inside loops. This deficiency in theory could be avoided by storing the set of globals and locals dicts to update in the _demandmod instance. However, I tried this and it didn't work. One reason is that some globals are _demandmod instances. We could work around this, but it's a bit more work. There also might be other module import foo at play. The solution as implemented is better than what we had and IMO is good enough for the time being. It's worth noting that this sub-optimal behavior was made worse by the introduction of absolute_import and its recommended "from . import X" syntax for importing modules from the "mercurial" package. If we ever wrote performance tests, measuring the amount of module imports and __getattribute__ proxy calls through _demandmod instances would be something I'd have it check.

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util.h
169 lines | 4.1 KiB | text/x-c | CLexer
/*
util.h - utility functions for interfacing with the various python APIs.
This software may be used and distributed according to the terms of
the GNU General Public License, incorporated herein by reference.
*/
#ifndef _HG_UTIL_H_
#define _HG_UTIL_H_
#if PY_MAJOR_VERSION >= 3
#define IS_PY3K
#define PyInt_FromLong PyLong_FromLong
#define PyInt_AsLong PyLong_AsLong
/*
Mapping of some of the python < 2.x PyString* functions to py3k's PyUnicode.
The commented names below represent those that are present in the PyBytes
definitions for python < 2.6 (below in this file) that don't have a direct
implementation.
*/
#define PyStringObject PyUnicodeObject
#define PyString_Type PyUnicode_Type
#define PyString_Check PyUnicode_Check
#define PyString_CheckExact PyUnicode_CheckExact
#define PyString_CHECK_INTERNED PyUnicode_CHECK_INTERNED
#define PyString_AS_STRING PyUnicode_AsLatin1String
#define PyString_GET_SIZE PyUnicode_GET_SIZE
#define PyString_FromStringAndSize PyUnicode_FromStringAndSize
#define PyString_FromString PyUnicode_FromString
#define PyString_FromFormatV PyUnicode_FromFormatV
#define PyString_FromFormat PyUnicode_FromFormat
/* #define PyString_Size PyUnicode_GET_SIZE */
/* #define PyString_AsString */
/* #define PyString_Repr */
#define PyString_Concat PyUnicode_Concat
#define PyString_ConcatAndDel PyUnicode_AppendAndDel
#define _PyString_Resize PyUnicode_Resize
/* #define _PyString_Eq */
#define PyString_Format PyUnicode_Format
/* #define _PyString_FormatLong */
/* #define PyString_DecodeEscape */
#define _PyString_Join PyUnicode_Join
#define PyString_Decode PyUnicode_Decode
#define PyString_Encode PyUnicode_Encode
#define PyString_AsEncodedObject PyUnicode_AsEncodedObject
#define PyString_AsEncodedString PyUnicode_AsEncodedString
#define PyString_AsDecodedObject PyUnicode_AsDecodedObject
#define PyString_AsDecodedString PyUnicode_AsDecodedUnicode
/* #define PyString_AsStringAndSize */
#define _PyString_InsertThousandsGrouping _PyUnicode_InsertThousandsGrouping
#endif /* PY_MAJOR_VERSION */
#ifdef _WIN32
#ifdef _MSC_VER
/* msvc 6.0 has problems */
#define inline __inline
typedef signed char int8_t;
typedef short int16_t;
typedef long int32_t;
typedef __int64 int64_t;
typedef unsigned char uint8_t;
typedef unsigned short uint16_t;
typedef unsigned long uint32_t;
typedef unsigned __int64 uint64_t;
#else
#include <stdint.h>
#endif
#else
/* not windows */
#include <sys/types.h>
#if defined __BEOS__ && !defined __HAIKU__
#include <ByteOrder.h>
#else
#include <arpa/inet.h>
#endif
#include <inttypes.h>
#endif
#if defined __hpux || defined __SUNPRO_C || defined _AIX
#define inline
#endif
#ifdef __linux
#define inline __inline
#endif
typedef struct {
PyObject_HEAD
char state;
int mode;
int size;
int mtime;
} dirstateTupleObject;
extern PyTypeObject dirstateTupleType;
#define dirstate_tuple_check(op) (Py_TYPE(op) == &dirstateTupleType)
static inline uint32_t getbe32(const char *c)
{
const unsigned char *d = (const unsigned char *)c;
return ((d[0] << 24) |
(d[1] << 16) |
(d[2] << 8) |
(d[3]));
}
static inline int16_t getbeint16(const char *c)
{
const unsigned char *d = (const unsigned char *)c;
return ((d[0] << 8) |
(d[1]));
}
static inline uint16_t getbeuint16(const char *c)
{
const unsigned char *d = (const unsigned char *)c;
return ((d[0] << 8) |
(d[1]));
}
static inline void putbe32(uint32_t x, char *c)
{
c[0] = (x >> 24) & 0xff;
c[1] = (x >> 16) & 0xff;
c[2] = (x >> 8) & 0xff;
c[3] = (x) & 0xff;
}
static inline double getbefloat64(const char *c)
{
const unsigned char *d = (const unsigned char *)c;
double ret;
int i;
uint64_t t = 0;
for (i = 0; i < 8; i++) {
t = (t<<8) + d[i];
}
memcpy(&ret, &t, sizeof(t));
return ret;
}
/* This should be kept in sync with normcasespecs in encoding.py. */
enum normcase_spec {
NORMCASE_LOWER = -1,
NORMCASE_UPPER = 1,
NORMCASE_OTHER = 0
};
#define MIN(a, b) (((a)<(b))?(a):(b))
/* VC9 doesn't include bool and lacks stdbool.h based on my searching */
#if defined(_MSC_VER) || __STDC_VERSION__ < 199901L
#define true 1
#define false 0
typedef unsigned char bool;
#else
#include <stdbool.h>
#endif
#endif /* _HG_UTIL_H_ */