✨ A1

A1/id_query.h

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+// This file (along with its implementation id_query.c) abstracts out
+// the user-facing part of the query programs.  It implements the
+// following algorithm:
+//
+// Records <- Read Dataset
+// Index <- Produce Index From Records
+// While Program Is Running:
+//   Read Query From User
+//   Lookup Query In Index
+// Free Index
+//
+// Where the specifics of "Produce Index From Records", "Lookup Query
+// In Index", and "Free Index" are provided via function pointers.
+// This means we can write the main loop just once, and reuse it with
+// different implementations of indexes.
+//
+// See the file id_query_naive.c for a usage example.
+
+#ifndef ID_QUERY_LOOP_H
+#define ID_QUERY_LOOP_H
+
+#include "record.h"
+
+// A pointer to a function that produces an index, when called with an
+// array of records and the size of the array.
+typedef void* (*mk_index_fn)(const struct record*, int);
+
+// Freeing an array produced by a mk_index_fn.
+typedef void (*free_index_fn)(void*);
+
+// Look up an ID in an index produced by mk_index_fn.
+typedef const struct record* (*lookup_fn)(void*, int64_t);
+
+// Run a query loop, using the provided functions for managing the
+// index.
+int id_query_loop(int argc, char** argv, mk_index_fn, free_index_fn, lookup_fn);
+
+#endif