Mercurial > hg
view mercurial/cext/util.h @ 45871:a985c4fb23ca
transaction: change list of journal entries into a dictionary
The transaction object used to keep a mapping table of path names to
journal entries and a list of journal entries consisting of path and
file offset to truncate on rollback. The offsets are used in three
cases. repair.strip and rollback process all of them in one go, but they
care about the order. For them, it is perfectly reasonable to read the
journal back from disk as both operations already involve at least one
system call per journal entry. The other consumer is the revlog logic
for moving from inline to external data storage. It doesn't care about
the order of the journal and just needs to original offset stored.
Further optimisations are possible here to move the in-memory journal to
a set(), but without memoisation of the original revlog size this could
turn it into O(n^2) behavior in worst case when many revlogs need to
migrated.
Differential Revision: https://phab.mercurial-scm.org/D9277
author | Joerg Sonnenberger <joerg@bec.de> |
---|---|
date | Sat, 07 Nov 2020 21:34:09 +0100 |
parents | fa33196088c4 |
children | 84391ddf4c78 |
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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_ #include "compat.h" #if PY_MAJOR_VERSION >= 3 #define IS_PY3K #endif /* helper to switch things like string literal depending on Python version */ #ifdef IS_PY3K #define PY23(py2, py3) py3 #else #define PY23(py2, py3) py2 #endif /* clang-format off */ typedef struct { PyObject_HEAD char state; int mode; int size; int mtime; } dirstateTupleObject; /* clang-format on */ extern PyTypeObject dirstateTupleType; #define dirstate_tuple_check(op) (Py_TYPE(op) == &dirstateTupleType) #ifndef MIN #define MIN(a, b) (((a) < (b)) ? (a) : (b)) #endif /* 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 static inline PyObject *_dict_new_presized(Py_ssize_t expected_size) { /* _PyDict_NewPresized expects a minused parameter, but it actually creates a dictionary that's the nearest power of two bigger than the parameter. For example, with the initial minused = 1000, the dictionary created has size 1024. Of course in a lot of cases that can be greater than the maximum load factor Python's dict object expects (= 2/3), so as soon as we cross the threshold we'll resize anyway. So create a dictionary that's at least 3/2 the size. */ return _PyDict_NewPresized(((1 + expected_size) / 2) * 3); } /* Convert a PyInt or PyLong to a long. Returns false if there is an error, in which case an exception will already have been set. */ static inline bool pylong_to_long(PyObject *pylong, long *out) { *out = PyLong_AsLong(pylong); /* Fast path to avoid hitting PyErr_Occurred if the value was obviously * not an error. */ if (*out != -1) { return true; } return PyErr_Occurred() == NULL; } #endif /* _HG_UTIL_H_ */