Mercurial > hg
diff mercurial/cext/revlog.c @ 45811:4404f129341e
revlog: don't cache parsed tuples in the C module
A cached entry creates ~8 Python objects per cached changeset, which
comes to around 200 Bytes per cached changeset on AMD64. Especially for
operations that touch a lot of changesets, that can easily sum up to
more than a 100MB of memory. Simple tests on large repositories show
<2% runtime penalty for ripping out the cache, even for cache heavy
operations like "hg log" for all revisions.
Differential Revision: https://phab.mercurial-scm.org/D9155
author | Joerg Sonnenberger <joerg@bec.de> |
---|---|
date | Tue, 06 Oct 2020 13:34:51 +0200 |
parents | a6fde9d789d9 |
children | 0ce15a8c7b8b |
line wrap: on
line diff
--- a/mercurial/cext/revlog.c Fri Oct 16 16:00:32 2020 -0700 +++ b/mercurial/cext/revlog.c Tue Oct 06 13:34:51 2020 +0200 @@ -81,7 +81,6 @@ /* Type-specific fields go here. */ PyObject *data; /* raw bytes of index */ Py_buffer buf; /* buffer of data */ - PyObject **cache; /* cached tuples */ const char **offsets; /* populated on demand */ Py_ssize_t raw_length; /* original number of elements */ Py_ssize_t length; /* current number of elements */ @@ -327,7 +326,6 @@ const char *c_node_id; const char *data; Py_ssize_t length = index_length(self); - PyObject *entry; if (pos == nullrev) { Py_INCREF(nullentry); @@ -346,17 +344,6 @@ return obj; } - if (self->cache) { - if (self->cache[pos]) { - Py_INCREF(self->cache[pos]); - return self->cache[pos]; - } - } else { - self->cache = calloc(self->raw_length, sizeof(PyObject *)); - if (self->cache == NULL) - return PyErr_NoMemory(); - } - data = index_deref(self, pos); if (data == NULL) return NULL; @@ -377,18 +364,9 @@ parent_2 = getbe32(data + 28); c_node_id = data + 32; - entry = Py_BuildValue(tuple_format, offset_flags, comp_len, uncomp_len, - base_rev, link_rev, parent_1, parent_2, c_node_id, - (Py_ssize_t)20); - - if (entry) { - PyObject_GC_UnTrack(entry); - Py_INCREF(entry); - } - - self->cache[pos] = entry; - - return entry; + return Py_BuildValue(tuple_format, offset_flags, comp_len, uncomp_len, + base_rev, link_rev, parent_1, parent_2, c_node_id, + (Py_ssize_t)20); } /* @@ -2578,14 +2556,8 @@ } self->length = start; - if (start < self->raw_length) { - if (self->cache) { - Py_ssize_t i; - for (i = start; i < self->raw_length; i++) - Py_CLEAR(self->cache[i]); - } + if (start < self->raw_length) self->raw_length = start; - } goto done; } @@ -2677,7 +2649,6 @@ */ self->raw_length = 0; self->added = NULL; - self->cache = NULL; self->data = NULL; memset(&self->buf, 0, sizeof(self->buf)); self->headrevs = NULL; @@ -2733,14 +2704,6 @@ static void _index_clearcaches(indexObject *self) { - if (self->cache) { - Py_ssize_t i; - - for (i = 0; i < self->raw_length; i++) - Py_CLEAR(self->cache[i]); - free(self->cache); - self->cache = NULL; - } if (self->offsets) { PyMem_Free((void *)self->offsets); self->offsets = NULL;