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+#ifndef HASH_LOOKUP_H
+#define HASH_LOOKUP_H
+
+typedef const struct object_id *oid_access_fn(size_t index, const void *table);
+
+int oid_pos(const struct object_id *oid,
+ const void *table,
+ size_t nr,
+ oid_access_fn fn);
+
+/*
+ * Searches for hash in table, using the given fanout table to determine the
+ * interval to search, then using binary search. Returns 1 if found, 0 if not.
+ *
+ * Takes the following parameters:
+ *
+ * - hash: the hash to search for
+ * - fanout_nbo: a 256-element array of NETWORK-order 32-bit integers; the
+ * integer at position i represents the number of elements in table whose
+ * first byte is less than or equal to i
+ * - table: a sorted list of hashes with optional extra information in between
+ * - stride: distance between two consecutive elements in table (should be
+ * GIT_MAX_RAWSZ or greater)
+ * - result: if not NULL, this function stores the element index of the
+ * position found (if the search is successful) or the index of the least
+ * element that is greater than hash (if the search is not successful)
+ *
+ * This function does not verify the validity of the fanout table.
+ */
+int bsearch_hash(const unsigned char *hash, const uint32_t *fanout_nbo,
+ const unsigned char *table, size_t stride, uint32_t *result);
+#endif