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-rw-r--r--third_party/git/pack-revindex.c205
1 files changed, 0 insertions, 205 deletions
diff --git a/third_party/git/pack-revindex.c b/third_party/git/pack-revindex.c
deleted file mode 100644
index d28a7e43d0..0000000000
--- a/third_party/git/pack-revindex.c
+++ /dev/null
@@ -1,205 +0,0 @@
-#include "cache.h"
-#include "pack-revindex.h"
-#include "object-store.h"
-#include "packfile.h"
-
-/*
- * Pack index for existing packs give us easy access to the offsets into
- * corresponding pack file where each object's data starts, but the entries
- * do not store the size of the compressed representation (uncompressed
- * size is easily available by examining the pack entry header).  It is
- * also rather expensive to find the sha1 for an object given its offset.
- *
- * The pack index file is sorted by object name mapping to offset;
- * this revindex array is a list of offset/index_nr pairs
- * ordered by offset, so if you know the offset of an object, next offset
- * is where its packed representation ends and the index_nr can be used to
- * get the object sha1 from the main index.
- */
-
-/*
- * This is a least-significant-digit radix sort.
- *
- * It sorts each of the "n" items in "entries" by its offset field. The "max"
- * parameter must be at least as large as the largest offset in the array,
- * and lets us quit the sort early.
- */
-static void sort_revindex(struct revindex_entry *entries, unsigned n, off_t max)
-{
-	/*
-	 * We use a "digit" size of 16 bits. That keeps our memory
-	 * usage reasonable, and we can generally (for a 4G or smaller
-	 * packfile) quit after two rounds of radix-sorting.
-	 */
-#define DIGIT_SIZE (16)
-#define BUCKETS (1 << DIGIT_SIZE)
-	/*
-	 * We want to know the bucket that a[i] will go into when we are using
-	 * the digit that is N bits from the (least significant) end.
-	 */
-#define BUCKET_FOR(a, i, bits) (((a)[(i)].offset >> (bits)) & (BUCKETS-1))
-
-	/*
-	 * We need O(n) temporary storage. Rather than do an extra copy of the
-	 * partial results into "entries", we sort back and forth between the
-	 * real array and temporary storage. In each iteration of the loop, we
-	 * keep track of them with alias pointers, always sorting from "from"
-	 * to "to".
-	 */
-	struct revindex_entry *tmp, *from, *to;
-	int bits;
-	unsigned *pos;
-
-	ALLOC_ARRAY(pos, BUCKETS);
-	ALLOC_ARRAY(tmp, n);
-	from = entries;
-	to = tmp;
-
-	/*
-	 * If (max >> bits) is zero, then we know that the radix digit we are
-	 * on (and any higher) will be zero for all entries, and our loop will
-	 * be a no-op, as everybody lands in the same zero-th bucket.
-	 */
-	for (bits = 0; max >> bits; bits += DIGIT_SIZE) {
-		unsigned i;
-
-		memset(pos, 0, BUCKETS * sizeof(*pos));
-
-		/*
-		 * We want pos[i] to store the index of the last element that
-		 * will go in bucket "i" (actually one past the last element).
-		 * To do this, we first count the items that will go in each
-		 * bucket, which gives us a relative offset from the last
-		 * bucket. We can then cumulatively add the index from the
-		 * previous bucket to get the true index.
-		 */
-		for (i = 0; i < n; i++)
-			pos[BUCKET_FOR(from, i, bits)]++;
-		for (i = 1; i < BUCKETS; i++)
-			pos[i] += pos[i-1];
-
-		/*
-		 * Now we can drop the elements into their correct buckets (in
-		 * our temporary array).  We iterate the pos counter backwards
-		 * to avoid using an extra index to count up. And since we are
-		 * going backwards there, we must also go backwards through the
-		 * array itself, to keep the sort stable.
-		 *
-		 * Note that we use an unsigned iterator to make sure we can
-		 * handle 2^32-1 objects, even on a 32-bit system. But this
-		 * means we cannot use the more obvious "i >= 0" loop condition
-		 * for counting backwards, and must instead check for
-		 * wrap-around with UINT_MAX.
-		 */
-		for (i = n - 1; i != UINT_MAX; i--)
-			to[--pos[BUCKET_FOR(from, i, bits)]] = from[i];
-
-		/*
-		 * Now "to" contains the most sorted list, so we swap "from" and
-		 * "to" for the next iteration.
-		 */
-		SWAP(from, to);
-	}
-
-	/*
-	 * If we ended with our data in the original array, great. If not,
-	 * we have to move it back from the temporary storage.
-	 */
-	if (from != entries)
-		COPY_ARRAY(entries, tmp, n);
-	free(tmp);
-	free(pos);
-
-#undef BUCKET_FOR
-#undef BUCKETS
-#undef DIGIT_SIZE
-}
-
-/*
- * Ordered list of offsets of objects in the pack.
- */
-static void create_pack_revindex(struct packed_git *p)
-{
-	const unsigned num_ent = p->num_objects;
-	unsigned i;
-	const char *index = p->index_data;
-	const unsigned hashsz = the_hash_algo->rawsz;
-
-	ALLOC_ARRAY(p->revindex, num_ent + 1);
-	index += 4 * 256;
-
-	if (p->index_version > 1) {
-		const uint32_t *off_32 =
-			(uint32_t *)(index + 8 + p->num_objects * (hashsz + 4));
-		const uint32_t *off_64 = off_32 + p->num_objects;
-		for (i = 0; i < num_ent; i++) {
-			const uint32_t off = ntohl(*off_32++);
-			if (!(off & 0x80000000)) {
-				p->revindex[i].offset = off;
-			} else {
-				p->revindex[i].offset = get_be64(off_64);
-				off_64 += 2;
-			}
-			p->revindex[i].nr = i;
-		}
-	} else {
-		for (i = 0; i < num_ent; i++) {
-			const uint32_t hl = *((uint32_t *)(index + (hashsz + 4) * i));
-			p->revindex[i].offset = ntohl(hl);
-			p->revindex[i].nr = i;
-		}
-	}
-
-	/*
-	 * This knows the pack format -- the hash trailer
-	 * follows immediately after the last object data.
-	 */
-	p->revindex[num_ent].offset = p->pack_size - hashsz;
-	p->revindex[num_ent].nr = -1;
-	sort_revindex(p->revindex, num_ent, p->pack_size);
-}
-
-int load_pack_revindex(struct packed_git *p)
-{
-	if (!p->revindex) {
-		if (open_pack_index(p))
-			return -1;
-		create_pack_revindex(p);
-	}
-	return 0;
-}
-
-int find_revindex_position(struct packed_git *p, off_t ofs)
-{
-	int lo = 0;
-	int hi = p->num_objects + 1;
-	const struct revindex_entry *revindex = p->revindex;
-
-	do {
-		const unsigned mi = lo + (hi - lo) / 2;
-		if (revindex[mi].offset == ofs) {
-			return mi;
-		} else if (ofs < revindex[mi].offset)
-			hi = mi;
-		else
-			lo = mi + 1;
-	} while (lo < hi);
-
-	error("bad offset for revindex");
-	return -1;
-}
-
-struct revindex_entry *find_pack_revindex(struct packed_git *p, off_t ofs)
-{
-	int pos;
-
-	if (load_pack_revindex(p))
-		return NULL;
-
-	pos = find_revindex_position(p, ofs);
-
-	if (pos < 0)
-		return NULL;
-
-	return p->revindex + pos;
-}