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50f03c6676
A common pattern to free a piece of memory and assign NULL to the pointer that used to point at it has been replaced with a new FREE_AND_NULL() macro. * ab/free-and-null: *.[ch] refactoring: make use of the FREE_AND_NULL() macro coccinelle: make use of the "expression" FREE_AND_NULL() rule coccinelle: add a rule to make "expression" code use FREE_AND_NULL() coccinelle: make use of the "type" FREE_AND_NULL() rule coccinelle: add a rule to make "type" code use FREE_AND_NULL() git-compat-util: add a FREE_AND_NULL() wrapper around free(ptr); ptr = NULL
340 lines
9.5 KiB
C
340 lines
9.5 KiB
C
#include "cache.h"
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#include "split-index.h"
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#include "ewah/ewok.h"
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struct split_index *init_split_index(struct index_state *istate)
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{
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if (!istate->split_index) {
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istate->split_index = xcalloc(1, sizeof(*istate->split_index));
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istate->split_index->refcount = 1;
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}
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return istate->split_index;
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}
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int read_link_extension(struct index_state *istate,
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const void *data_, unsigned long sz)
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{
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const unsigned char *data = data_;
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struct split_index *si;
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int ret;
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if (sz < 20)
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return error("corrupt link extension (too short)");
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si = init_split_index(istate);
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hashcpy(si->base_sha1, data);
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data += 20;
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sz -= 20;
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if (!sz)
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return 0;
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si->delete_bitmap = ewah_new();
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ret = ewah_read_mmap(si->delete_bitmap, data, sz);
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if (ret < 0)
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return error("corrupt delete bitmap in link extension");
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data += ret;
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sz -= ret;
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si->replace_bitmap = ewah_new();
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ret = ewah_read_mmap(si->replace_bitmap, data, sz);
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if (ret < 0)
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return error("corrupt replace bitmap in link extension");
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if (ret != sz)
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return error("garbage at the end of link extension");
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return 0;
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}
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int write_link_extension(struct strbuf *sb,
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struct index_state *istate)
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{
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struct split_index *si = istate->split_index;
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strbuf_add(sb, si->base_sha1, 20);
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if (!si->delete_bitmap && !si->replace_bitmap)
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return 0;
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ewah_serialize_strbuf(si->delete_bitmap, sb);
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ewah_serialize_strbuf(si->replace_bitmap, sb);
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return 0;
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}
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static void mark_base_index_entries(struct index_state *base)
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{
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int i;
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/*
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* To keep track of the shared entries between
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* istate->base->cache[] and istate->cache[], base entry
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* position is stored in each base entry. All positions start
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* from 1 instead of 0, which is reserved to say "this is a new
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* entry".
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*/
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for (i = 0; i < base->cache_nr; i++)
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base->cache[i]->index = i + 1;
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}
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void move_cache_to_base_index(struct index_state *istate)
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{
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struct split_index *si = istate->split_index;
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int i;
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/*
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* do not delete old si->base, its index entries may be shared
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* with istate->cache[]. Accept a bit of leaking here because
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* this code is only used by short-lived update-index.
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*/
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si->base = xcalloc(1, sizeof(*si->base));
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si->base->version = istate->version;
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/* zero timestamp disables racy test in ce_write_index() */
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si->base->timestamp = istate->timestamp;
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ALLOC_GROW(si->base->cache, istate->cache_nr, si->base->cache_alloc);
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si->base->cache_nr = istate->cache_nr;
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COPY_ARRAY(si->base->cache, istate->cache, istate->cache_nr);
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mark_base_index_entries(si->base);
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for (i = 0; i < si->base->cache_nr; i++)
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si->base->cache[i]->ce_flags &= ~CE_UPDATE_IN_BASE;
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}
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static void mark_entry_for_delete(size_t pos, void *data)
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{
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struct index_state *istate = data;
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if (pos >= istate->cache_nr)
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die("position for delete %d exceeds base index size %d",
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(int)pos, istate->cache_nr);
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istate->cache[pos]->ce_flags |= CE_REMOVE;
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istate->split_index->nr_deletions = 1;
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}
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static void replace_entry(size_t pos, void *data)
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{
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struct index_state *istate = data;
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struct split_index *si = istate->split_index;
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struct cache_entry *dst, *src;
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if (pos >= istate->cache_nr)
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die("position for replacement %d exceeds base index size %d",
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(int)pos, istate->cache_nr);
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if (si->nr_replacements >= si->saved_cache_nr)
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die("too many replacements (%d vs %d)",
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si->nr_replacements, si->saved_cache_nr);
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dst = istate->cache[pos];
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if (dst->ce_flags & CE_REMOVE)
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die("entry %d is marked as both replaced and deleted",
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(int)pos);
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src = si->saved_cache[si->nr_replacements];
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if (ce_namelen(src))
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die("corrupt link extension, entry %d should have "
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"zero length name", (int)pos);
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src->index = pos + 1;
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src->ce_flags |= CE_UPDATE_IN_BASE;
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src->ce_namelen = dst->ce_namelen;
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copy_cache_entry(dst, src);
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free(src);
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si->nr_replacements++;
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}
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void merge_base_index(struct index_state *istate)
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{
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struct split_index *si = istate->split_index;
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unsigned int i;
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mark_base_index_entries(si->base);
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si->saved_cache = istate->cache;
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si->saved_cache_nr = istate->cache_nr;
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istate->cache_nr = si->base->cache_nr;
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istate->cache = NULL;
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istate->cache_alloc = 0;
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ALLOC_GROW(istate->cache, istate->cache_nr, istate->cache_alloc);
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COPY_ARRAY(istate->cache, si->base->cache, istate->cache_nr);
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si->nr_deletions = 0;
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si->nr_replacements = 0;
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ewah_each_bit(si->replace_bitmap, replace_entry, istate);
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ewah_each_bit(si->delete_bitmap, mark_entry_for_delete, istate);
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if (si->nr_deletions)
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remove_marked_cache_entries(istate);
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for (i = si->nr_replacements; i < si->saved_cache_nr; i++) {
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if (!ce_namelen(si->saved_cache[i]))
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die("corrupt link extension, entry %d should "
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"have non-zero length name", i);
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add_index_entry(istate, si->saved_cache[i],
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ADD_CACHE_OK_TO_ADD |
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ADD_CACHE_KEEP_CACHE_TREE |
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/*
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* we may have to replay what
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* merge-recursive.c:update_stages()
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* does, which has this flag on
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*/
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ADD_CACHE_SKIP_DFCHECK);
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si->saved_cache[i] = NULL;
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}
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ewah_free(si->delete_bitmap);
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ewah_free(si->replace_bitmap);
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FREE_AND_NULL(si->saved_cache);
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si->delete_bitmap = NULL;
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si->replace_bitmap = NULL;
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si->saved_cache_nr = 0;
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}
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void prepare_to_write_split_index(struct index_state *istate)
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{
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struct split_index *si = init_split_index(istate);
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struct cache_entry **entries = NULL, *ce;
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int i, nr_entries = 0, nr_alloc = 0;
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si->delete_bitmap = ewah_new();
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si->replace_bitmap = ewah_new();
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if (si->base) {
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/* Go through istate->cache[] and mark CE_MATCHED to
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* entry with positive index. We'll go through
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* base->cache[] later to delete all entries in base
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* that are not marked with either CE_MATCHED or
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* CE_UPDATE_IN_BASE. If istate->cache[i] is a
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* duplicate, deduplicate it.
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*/
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for (i = 0; i < istate->cache_nr; i++) {
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struct cache_entry *base;
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/* namelen is checked separately */
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const unsigned int ondisk_flags =
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CE_STAGEMASK | CE_VALID | CE_EXTENDED_FLAGS;
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unsigned int ce_flags, base_flags, ret;
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ce = istate->cache[i];
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if (!ce->index)
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continue;
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if (ce->index > si->base->cache_nr) {
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ce->index = 0;
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continue;
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}
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ce->ce_flags |= CE_MATCHED; /* or "shared" */
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base = si->base->cache[ce->index - 1];
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if (ce == base)
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continue;
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if (ce->ce_namelen != base->ce_namelen ||
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strcmp(ce->name, base->name)) {
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ce->index = 0;
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continue;
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}
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ce_flags = ce->ce_flags;
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base_flags = base->ce_flags;
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/* only on-disk flags matter */
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ce->ce_flags &= ondisk_flags;
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base->ce_flags &= ondisk_flags;
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ret = memcmp(&ce->ce_stat_data, &base->ce_stat_data,
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offsetof(struct cache_entry, name) -
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offsetof(struct cache_entry, ce_stat_data));
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ce->ce_flags = ce_flags;
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base->ce_flags = base_flags;
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if (ret)
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ce->ce_flags |= CE_UPDATE_IN_BASE;
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free(base);
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si->base->cache[ce->index - 1] = ce;
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}
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for (i = 0; i < si->base->cache_nr; i++) {
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ce = si->base->cache[i];
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if ((ce->ce_flags & CE_REMOVE) ||
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!(ce->ce_flags & CE_MATCHED))
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ewah_set(si->delete_bitmap, i);
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else if (ce->ce_flags & CE_UPDATE_IN_BASE) {
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ewah_set(si->replace_bitmap, i);
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ce->ce_flags |= CE_STRIP_NAME;
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ALLOC_GROW(entries, nr_entries+1, nr_alloc);
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entries[nr_entries++] = ce;
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}
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}
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}
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for (i = 0; i < istate->cache_nr; i++) {
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ce = istate->cache[i];
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if ((!si->base || !ce->index) && !(ce->ce_flags & CE_REMOVE)) {
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assert(!(ce->ce_flags & CE_STRIP_NAME));
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ALLOC_GROW(entries, nr_entries+1, nr_alloc);
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entries[nr_entries++] = ce;
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}
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ce->ce_flags &= ~CE_MATCHED;
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}
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/*
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* take cache[] out temporarily, put entries[] in its place
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* for writing
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*/
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si->saved_cache = istate->cache;
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si->saved_cache_nr = istate->cache_nr;
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istate->cache = entries;
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istate->cache_nr = nr_entries;
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}
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void finish_writing_split_index(struct index_state *istate)
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{
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struct split_index *si = init_split_index(istate);
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ewah_free(si->delete_bitmap);
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ewah_free(si->replace_bitmap);
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si->delete_bitmap = NULL;
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si->replace_bitmap = NULL;
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free(istate->cache);
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istate->cache = si->saved_cache;
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istate->cache_nr = si->saved_cache_nr;
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}
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void discard_split_index(struct index_state *istate)
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{
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struct split_index *si = istate->split_index;
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if (!si)
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return;
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istate->split_index = NULL;
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si->refcount--;
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if (si->refcount)
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return;
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if (si->base) {
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discard_index(si->base);
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free(si->base);
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}
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free(si);
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}
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void save_or_free_index_entry(struct index_state *istate, struct cache_entry *ce)
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{
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if (ce->index &&
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istate->split_index &&
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istate->split_index->base &&
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ce->index <= istate->split_index->base->cache_nr &&
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ce == istate->split_index->base->cache[ce->index - 1])
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ce->ce_flags |= CE_REMOVE;
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else
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free(ce);
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}
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void replace_index_entry_in_base(struct index_state *istate,
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struct cache_entry *old,
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struct cache_entry *new)
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{
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if (old->index &&
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istate->split_index &&
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istate->split_index->base &&
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old->index <= istate->split_index->base->cache_nr) {
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new->index = old->index;
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if (old != istate->split_index->base->cache[new->index - 1])
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free(istate->split_index->base->cache[new->index - 1]);
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istate->split_index->base->cache[new->index - 1] = new;
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}
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}
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void add_split_index(struct index_state *istate)
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{
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if (!istate->split_index) {
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init_split_index(istate);
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istate->cache_changed |= SPLIT_INDEX_ORDERED;
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}
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}
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void remove_split_index(struct index_state *istate)
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{
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if (istate->split_index) {
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/*
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* can't discard_split_index(&the_index); because that
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* will destroy split_index->base->cache[], which may
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* be shared with the_index.cache[]. So yeah we're
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* leaking a bit here.
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*/
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istate->split_index = NULL;
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istate->cache_changed |= SOMETHING_CHANGED;
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}
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}
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