Mercurial > hg
view mercurial/util.h @ 29375:fcaf20175b1b
demandimport: delay loading for "from a import b" with absolute_import
Before this patch, "from a import b" doesn't delay loading module "b",
if absolute_import is enabled, even though "from . import b" does.
For example:
- it is assumed that extension X has "from P import M" for module M
under package P with absolute_import feature
- if importing module M is already delayed before loading extension
X, loading module M in extension X is delayed until actually
referring
util, cmdutil, scmutil or so of Mercurial itself should be
imported by "from . import M" style before loading extension X
- otherwise, module M is loaded immediately at loading extension X,
even if extension X itself isn't used at that "hg" command invocation
Some minor modules (e.g. filemerge or so) of Mercurial itself
aren't imported by "from . import M" style before loading
extension X. And of course, external libraries aren't, too.
This might cause startup performance problem of hg command, because
many bundled extensions already enable absolute_import feature.
To delay loading module for "from a import b" with absolute_import
feature, this patch does below in "from a (or .a) import b" with
absolute_import case:
1. import root module of "name" by system built-in __import__
(referred as _origimport)
2. recurse down the module chain for hierarchical "name"
This logic can be shared with non absolute_import
case. Therefore, this patch also centralizes it into chainmodules().
3. and fall through to process elements in "fromlist" for the leaf
module of "name"
Processing elements in "fromlist" is executed in the code path
after "if _pypy: .... else: ..." clause. Therefore, this patch
replaces "if _pypy:" with "elif _pypy:" to share it.
At 4f1144c3c72b introducing original "work around" for "from a import
b" case, elements in "fromlist" were imported with "level=level". But
"level" might be grater than 1 (e.g. level=2 in "from .. import b"
case) at demandimport() invocation, and importing direct sub-module in
"fromlist" with level grater than 1 causes unexpected result.
IMHO, this seems main reason of "errors for unknown reason" described
in 4f1144c3c72b, and we don't have to worry about it, because this
issue was already fixed by 78d05778907b.
This is reason why this patch removes "errors for unknown reasons"
comment.
author | FUJIWARA Katsunori <foozy@lares.dti.ne.jp> |
---|---|
date | Sun, 19 Jun 2016 02:17:33 +0900 |
parents | 14bf7679fb68 |
children | 284d742e5611 |
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/* 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_ */