( )⚙ D12177 revlog: memset whole record instead of dealing with padding

This is an archive of the discontinued Mercurial Phabricator instance.

Differential D12177

revlog: memset whole record instead of dealing with padding
ClosedPublic

Authored by pacien on Feb 14 2022, 1:06 PM.

Details

Reviewers
Alphare
Group Reviewers
hg-reviewers
Commits
rHG654baf1faa52: revlog: memset whole record instead of dealing with padding
Summary

This is less error-prone.

Diff Detail

Repository
rHG Mercurial
Branch
default
Lint
No Linters Available
Unit
No Unit Test Coverage

Event Timeline

pacien created this revision.Feb 14 2022, 1:06 PM
Alphare accepted this revision.Feb 15 2022, 8:03 AM
This revision is now accepted and ready to land.Feb 15 2022, 8:03 AM

Revision Contents
Changeset List

PathPackages
Mmercurial/cext/revlog.c (13 lines)

Diff 32176

mercurial/cext/revlog.c

static const long entry_v2_offset_base_rev = 16; static const long entry_v2_offset_base_rev = 16;
static const long entry_v2_offset_link_rev = 20; static const long entry_v2_offset_link_rev = 20;
static const long entry_v2_offset_parent_1 = 24; static const long entry_v2_offset_parent_1 = 24;
static const long entry_v2_offset_parent_2 = 28; static const long entry_v2_offset_parent_2 = 28;
static const long entry_v2_offset_node_id = 32; static const long entry_v2_offset_node_id = 32;
static const long entry_v2_offset_sidedata_offset = 64; static const long entry_v2_offset_sidedata_offset = 64;
static const long entry_v2_offset_sidedata_comp_len = 72; static const long entry_v2_offset_sidedata_comp_len = 72;
static const long entry_v2_offset_all_comp_mode = 76; static const long entry_v2_offset_all_comp_mode = 76;
static const long entry_v2_offset_padding_start = 77; /* next free offset: 77 */
static const char comp_mode_inline = 2; static const char comp_mode_inline = 2;
static const char rank_unknown = -1; static const char rank_unknown = -1;
static void raise_revlog_error(void) static void raise_revlog_error(void)
{ {
PyObject *mod = NULL, *dict = NULL, *errclass = NULL; PyObject *mod = NULL, *dict = NULL, *errclass = NULL;
if (!new_added) if (!new_added)
return PyErr_NoMemory(); return PyErr_NoMemory();
self->added = new_added; self->added = new_added;
self->added_length = new_added_length; self->added_length = new_added_length;
} }
rev = self->length + self->new_length; rev = self->length + self->new_length;
data = self->added + self->entry_size * self->new_length++; data = self->added + self->entry_size * self->new_length++;
memset(data, 0, self->entry_size);
if (self->format_version == format_v1) { if (self->format_version == format_v1) {
putbe32(offset_flags >> 32, data + entry_v1_offset_high); putbe32(offset_flags >> 32, data + entry_v1_offset_high);
putbe32(offset_flags & 0xffffffffU, putbe32(offset_flags & 0xffffffffU,
data + entry_v1_offset_offset_flags); data + entry_v1_offset_offset_flags);
putbe32(comp_len, data + entry_v1_offset_comp_len); putbe32(comp_len, data + entry_v1_offset_comp_len);
putbe32(uncomp_len, data + entry_v1_offset_uncomp_len); putbe32(uncomp_len, data + entry_v1_offset_uncomp_len);
putbe32(base_rev, data + entry_v1_offset_base_rev); putbe32(base_rev, data + entry_v1_offset_base_rev);
putbe32(link_rev, data + entry_v1_offset_link_rev); putbe32(link_rev, data + entry_v1_offset_link_rev);
putbe32(parent_1, data + entry_v1_offset_parent_1); putbe32(parent_1, data + entry_v1_offset_parent_1);
putbe32(parent_2, data + entry_v1_offset_parent_2); putbe32(parent_2, data + entry_v1_offset_parent_2);
memcpy(data + entry_v1_offset_node_id, c_node_id, memcpy(data + entry_v1_offset_node_id, c_node_id,
c_node_id_len); c_node_id_len);
/* Padding since SHA-1 is only 20 bytes for now */
memset(data + entry_v1_offset_node_id + c_node_id_len, 0,
entry_v1_offset_node_id - c_node_id_len);
} else if (self->format_version == format_v2) { } else if (self->format_version == format_v2) {
putbe32(offset_flags >> 32, data + entry_v2_offset_high); putbe32(offset_flags >> 32, data + entry_v2_offset_high);
putbe32(offset_flags & 0xffffffffU, putbe32(offset_flags & 0xffffffffU,
data + entry_v2_offset_offset_flags); data + entry_v2_offset_offset_flags);
putbe32(comp_len, data + entry_v2_offset_comp_len); putbe32(comp_len, data + entry_v2_offset_comp_len);
putbe32(uncomp_len, data + entry_v2_offset_uncomp_len); putbe32(uncomp_len, data + entry_v2_offset_uncomp_len);
putbe32(base_rev, data + entry_v2_offset_base_rev); putbe32(base_rev, data + entry_v2_offset_base_rev);
putbe32(link_rev, data + entry_v2_offset_link_rev); putbe32(link_rev, data + entry_v2_offset_link_rev);
putbe32(parent_1, data + entry_v2_offset_parent_1); putbe32(parent_1, data + entry_v2_offset_parent_1);
putbe32(parent_2, data + entry_v2_offset_parent_2); putbe32(parent_2, data + entry_v2_offset_parent_2);
memcpy(data + entry_v2_offset_node_id, c_node_id, memcpy(data + entry_v2_offset_node_id, c_node_id,
c_node_id_len); c_node_id_len);
/* Padding since SHA-1 is only 20 bytes for now */
memset(data + entry_v2_offset_node_id + c_node_id_len, 0,
entry_v2_offset_node_id - c_node_id_len);
putbe64(sidedata_offset, putbe64(sidedata_offset,
data + entry_v2_offset_sidedata_offset); data + entry_v2_offset_sidedata_offset);
putbe32(sidedata_comp_len, putbe32(sidedata_comp_len,
data + entry_v2_offset_sidedata_comp_len); data + entry_v2_offset_sidedata_comp_len);
comp_field = data_comp_mode & 3; comp_field = data_comp_mode & 3;
comp_field = comp_field | (sidedata_comp_mode & 3) << 2; comp_field = comp_field | (sidedata_comp_mode & 3) << 2;
data[entry_v2_offset_all_comp_mode] = comp_field; data[entry_v2_offset_all_comp_mode] = comp_field;
/* Padding for 96 bytes alignment */
memset(data + entry_v2_offset_padding_start, 0,
self->entry_size - entry_v2_offset_padding_start);
} else { } else {
raise_revlog_error(); raise_revlog_error();
return NULL; return NULL;
} }
if (self->ntinitialized) if (self->ntinitialized)
nt_insert(&self->nt, c_node_id, rev); nt_insert(&self->nt, c_node_id, rev);