initial

include/libart/art.h

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+#include <stdint.h>
+#ifndef ART_H
+#define ART_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define NODE4   1
+#define NODE16  2
+#define NODE48  3
+#define NODE256 4
+
+#define MAX_PREFIX_LEN 10
+
+#if defined(__GNUC__) && !defined(__clang__)
+# if __STDC_VERSION__ >= 199901L && 402 == (__GNUC__ * 100 + __GNUC_MINOR__)
+/*
+ * GCC 4.2.2's C99 inline keyword support is pretty broken; avoid. Introduced in
+ * GCC 4.2.something, fixed in 4.3.0. So checking for specific major.minor of
+ * 4.2 is fine.
+ */
+#  define BROKEN_GCC_C99_INLINE
+# endif
+#endif
+
+typedef int(*art_callback)(void *data, const unsigned char *key, uint32_t key_len, void *value);
+
+/**
+ * This struct is included as part
+ * of all the various node sizes
+ */
+typedef struct {
+    uint32_t partial_len;
+    uint8_t type;
+    uint8_t num_children;
+    unsigned char partial[MAX_PREFIX_LEN];
+} art_node;
+
+/**
+ * Small node with only 4 children
+ */
+typedef struct {
+    art_node n;
+    unsigned char keys[4];
+    art_node *children[4];
+} art_node4;
+
+/**
+ * Node with 16 children
+ */
+typedef struct {
+    art_node n;
+    unsigned char keys[16];
+    art_node *children[16];
+} art_node16;
+
+/**
+ * Node with 48 children, but
+ * a full 256 byte field.
+ */
+typedef struct {
+    art_node n;
+    unsigned char keys[256];
+    art_node *children[48];
+} art_node48;
+
+/**
+ * Full node with 256 children
+ */
+typedef struct {
+    art_node n;
+    art_node *children[256];
+} art_node256;
+
+/**
+ * Represents a leaf. These are
+ * of arbitrary size, as they include the key.
+ */
+typedef struct {
+    void *value;
+    uint32_t key_len;
+    unsigned char key[];
+} art_leaf;
+
+/**
+ * Main struct, points to root.
+ */
+typedef struct {
+    art_node *root;
+    uint64_t size;
+} art_tree;
+
+/**
+ * Initializes an ART tree
+ * @return 0 on success.
+ */
+int art_tree_init(art_tree *t);
+
+/**
+ * DEPRECATED
+ * Initializes an ART tree
+ * @return 0 on success.
+ */
+#define init_art_tree(...) art_tree_init(__VA_ARGS__)
+
+/**
+ * Destroys an ART tree
+ * @return 0 on success.
+ */
+int art_tree_destroy(art_tree *t);
+
+/**
+ * DEPRECATED
+ * Initializes an ART tree
+ * @return 0 on success.
+ */
+#define destroy_art_tree(...) art_tree_destroy(__VA_ARGS__)
+
+/**
+ * Returns the size of the ART tree.
+ */
+#ifdef BROKEN_GCC_C99_INLINE
+# define art_size(t) ((t)->size)
+#else
+inline uint64_t art_size(art_tree *t) {
+    return t->size;
+}
+#endif
+
+/**
+ * inserts a new value into the art tree
+ * @arg t the tree
+ * @arg key the key
+ * @arg key_len the length of the key
+ * @arg value opaque value.
+ * @return null if the item was newly inserted, otherwise
+ * the old value pointer is returned.
+ */
+void* art_insert(art_tree *t, const unsigned char *key, int key_len, void *value);
+
+/**
+ * inserts a new value into the art tree (not replacing)
+ * @arg t the tree
+ * @arg key the key
+ * @arg key_len the length of the key
+ * @arg value opaque value.
+ * @return null if the item was newly inserted, otherwise
+ * the old value pointer is returned.
+ */
+void* art_insert_no_replace(art_tree *t, const unsigned char *key, int key_len, void *value);
+
+/**
+ * Deletes a value from the ART tree
+ * @arg t The tree
+ * @arg key The key
+ * @arg key_len The length of the key
+ * @return NULL if the item was not found, otherwise
+ * the value pointer is returned.
+ */
+void* art_delete(art_tree *t, const unsigned char *key, int key_len);
+
+/**
+ * Searches for a value in the ART tree
+ * @arg t The tree
+ * @arg key The key
+ * @arg key_len The length of the key
+ * @return NULL if the item was not found, otherwise
+ * the value pointer is returned.
+ */
+void* art_search(const art_tree *t, const unsigned char *key, int key_len);
+
+/**
+ * Returns the minimum valued leaf
+ * @return The minimum leaf or NULL
+ */
+art_leaf* art_minimum(art_tree *t);
+
+/**
+ * Returns the maximum valued leaf
+ * @return The maximum leaf or NULL
+ */
+art_leaf* art_maximum(art_tree *t);
+
+/**
+ * Iterates through the entries pairs in the map,
+ * invoking a callback for each. The call back gets a
+ * key, value for each and returns an integer stop value.
+ * If the callback returns non-zero, then the iteration stops.
+ * @arg t The tree to iterate over
+ * @arg cb The callback function to invoke
+ * @arg data Opaque handle passed to the callback
+ * @return 0 on success, or the return of the callback.
+ */
+int art_iter(art_tree *t, art_callback cb, void *data);
+
+/**
+ * Iterates through the entries pairs in the map,
+ * invoking a callback for each that matches a given prefix.
+ * The call back gets a key, value for each and returns an integer stop value.
+ * If the callback returns non-zero, then the iteration stops.
+ * @arg t The tree to iterate over
+ * @arg prefix The prefix of keys to read
+ * @arg prefix_len The length of the prefix
+ * @arg cb The callback function to invoke
+ * @arg data Opaque handle passed to the callback
+ * @return 0 on success, or the return of the callback.
+ */
+int art_iter_prefix(art_tree *t, const unsigned char *prefix, int prefix_len, art_callback cb, void *data);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif