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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-10-07 15:26:32 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-10-07 15:34:22 +0200
commitc973bcc1039b64ec00acaf8e8d61b9f5229da56f (patch)
tree9aedf6df3a56ad02e2f9a369dbc6ff4264b349a5 /include/util/str_table.h
parentf731af6f58a7623b79241961d0a9a362b3e2ddb3 (diff)
Cleanup: move libutil related headers to "util" sub directory
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'include/util/str_table.h')
-rw-r--r--include/util/str_table.h53
1 files changed, 53 insertions, 0 deletions
diff --git a/include/util/str_table.h b/include/util/str_table.h
new file mode 100644
index 0000000..60be1d1
--- /dev/null
+++ b/include/util/str_table.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * str_table.h
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#ifndef STR_TABLE_H
+#define STR_TABLE_H
+
+#include "sqfs/predef.h"
+
+typedef struct str_bucket_t {
+ struct str_bucket_t *next;
+ char *str;
+ size_t index;
+ size_t refcount;
+} str_bucket_t;
+
+/* Stores strings in a hash table and assigns an incremental, unique ID to
+ each string. Subsequent additions return the existing ID. The ID can be
+ used for (hopefully) constant time lookup of the original string. */
+typedef struct {
+ str_bucket_t **buckets;
+ size_t num_buckets;
+
+ char **strings;
+ size_t num_strings;
+ size_t max_strings;
+} str_table_t;
+
+/* `size` is the number of hash table buckets to use internally. */
+SQFS_INTERNAL int str_table_init(str_table_t *table, size_t size);
+
+SQFS_INTERNAL void str_table_cleanup(str_table_t *table);
+
+/* Resolve a string to an incremental, unique ID. */
+SQFS_INTERNAL
+int str_table_get_index(str_table_t *table, const char *str, size_t *idx);
+
+/* Resolve a unique ID to the string it represents.
+ Returns NULL if the ID is unknown, i.e. out of bounds. */
+SQFS_INTERNAL
+const char *str_table_get_string(str_table_t *table, size_t index);
+
+SQFS_INTERNAL void str_table_reset_ref_count(str_table_t *table);
+
+SQFS_INTERNAL void str_table_add_ref(str_table_t *table, size_t index);
+
+SQFS_INTERNAL void str_table_del_ref(str_table_t *table, size_t index);
+
+SQFS_INTERNAL size_t str_table_get_ref_count(str_table_t *table, size_t index);
+
+#endif /* STR_TABLE_H */