Remove glib dependency

git-svn-id: http://svn.drobilla.net/sord/trunk@163 3d64ff67-21c5-427c-a301-fe4f08042e5a

5 files changed, 1079 insertions, 0 deletions

diff --git a/src/zix/common.h b/src/zix/common.h
new file mode 100644
index 0000000..a7edf76
--- /dev/null
+++ b/src/zix/common.h
@@ -0,0 +1,67 @@
+/*
+  Copyright 2011 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef ZIX_COMMON_H
+#define ZIX_COMMON_H
+
+#include <stdbool.h>
+
+/**
+   @addtogroup zix
+   @{
+*/
+
+/** @cond */
+#ifdef ZIX_SHARED
+#    ifdef __WIN32__
+#        define ZIX_LIB_IMPORT __declspec(dllimport)
+#        define ZIX_LIB_EXPORT __declspec(dllexport)
+#    else
+#        define ZIX_LIB_IMPORT __attribute__((visibility("default")))
+#        define ZIX_LIB_EXPORT __attribute__((visibility("default")))
+#    endif
+#    ifdef ZIX_INTERNAL
+#        define ZIX_API ZIX_LIB_EXPORT
+#    else
+#        define ZIX_API ZIX_LIB_IMPORT
+#    endif
+#else
+#    define ZIX_API
+#endif
+/** @endcond */
+
+typedef enum {
+	ZIX_STATUS_SUCCESS,
+	ZIX_STATUS_ERROR,
+	ZIX_STATUS_NO_MEM,
+	ZIX_STATUS_NOT_FOUND,
+	ZIX_STATUS_EXISTS,
+} ZixStatus;
+
+/**
+   Function for comparing two elements.
+*/
+typedef int (*ZixComparator)(const void* a, const void* b, void* user_data);
+
+/**
+   Function for testing equality of two elements.
+*/
+typedef bool (*ZixEqualFunc)(const void* a, const void* b);
+   
+/**@}
+*/
+
+#endif  /* ZIX_COMMON_H */
diff --git a/src/zix/hash.c b/src/zix/hash.c
new file mode 100644
index 0000000..c267757
--- /dev/null
+++ b/src/zix/hash.c
@@ -0,0 +1,226 @@
+/*
+  Copyright 2011 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "zix/hash.h"
+
+/**
+   Primes, each slightly less than twice its predecessor, and as far away
+   from powers of two as possible.
+*/
+static const unsigned sizes[] = {
+	53, 97, 193, 389, 769, 1543, 3079, 6151, 12289, 24593, 49157, 98317,
+	196613, 393241, 786433, 1572869, 3145739, 6291469, 12582917, 25165843,
+	50331653, 100663319, 201326611, 402653189, 805306457, 1610612741, 0
+};
+
+typedef struct _Entry {
+	const void*    key;   ///< Hash key
+	void*          data;  ///< Value
+	struct _Entry* next;  ///< Next entry in bucket
+	unsigned       hash;  ///< Non-modulo hash value (for cheap rehash)
+} Entry;
+
+struct ZixHashImpl {
+	ZixHashFunc     hash_func;
+	ZixEqualFunc    key_equal_func;
+	Entry**         buckets;
+	const unsigned* n_buckets;
+	unsigned        count;
+};
+
+ZixHash*
+zix_hash_new(ZixHashFunc  hash_func,
+             ZixEqualFunc key_equal_func)
+
+{
+	ZixHash* hash = (ZixHash*)malloc(sizeof(ZixHash));
+	hash->hash_func      = hash_func;
+	hash->key_equal_func = key_equal_func;
+	hash->count          = 0;
+	hash->n_buckets      = &sizes[0];
+	hash->buckets        = malloc(*hash->n_buckets * sizeof(Entry*));
+	memset(hash->buckets, 0, *hash->n_buckets * sizeof(Entry*));
+
+	return hash;
+}
+
+void
+zix_hash_free(ZixHash* hash)
+{
+	for (unsigned b = 0; b < *hash->n_buckets; ++b) {
+		Entry* bucket = hash->buckets[b];
+		for (Entry* e = bucket; e;) {
+			Entry* next = e->next;
+			free(e);
+			e = next;
+		}
+	}
+
+	free(hash->buckets);
+	free(hash);
+}
+
+unsigned
+zix_string_hash(const void* key)
+{
+	// Trusty old DJB hash
+	const char* str = (const char*)key;
+	unsigned    h   = 5381;
+	for (const char* s = str; *s != '\0'; ++s) {
+		h = (h << 5) + h + *s;  // h = h * 33 + c
+	}
+	return h;
+}
+
+bool
+zix_string_equal(const void* a, const void* b)
+{
+	return !strcmp((const char*)a, (const char*)b);
+}
+
+static void
+insert_entry(Entry** bucket,
+             Entry*  entry)
+{
+	entry->next = *bucket;
+	*bucket     = entry;
+}
+
+static ZixStatus
+rehash(ZixHash* hash, unsigned new_n_buckets)
+{
+	Entry** new_buckets = (Entry**)malloc(new_n_buckets * sizeof(Entry*));
+	if (!new_buckets) {
+		return ZIX_STATUS_NO_MEM;
+	}
+
+	memset(new_buckets, 0, new_n_buckets * sizeof(Entry*));
+
+	for (unsigned b = 0; b < *hash->n_buckets; ++b) {
+		for (Entry* e = hash->buckets[b]; e;) {
+			Entry* const   next = e->next;
+			const unsigned h    = e->hash % new_n_buckets;
+			insert_entry(&new_buckets[h], e);
+			e = next;
+		}
+	}
+
+	free(hash->buckets);
+	hash->buckets = new_buckets;
+
+	return ZIX_STATUS_SUCCESS;
+}
+
+static Entry*
+find_entry(const ZixHash* hash,
+           const void*    key,
+           unsigned   h)
+{
+	for (Entry* e = hash->buckets[h]; e; e = e->next) {
+		if (hash->key_equal_func(e->key, key)) {
+			return e;
+		}
+	}
+
+	return NULL;
+}
+
+void*
+zix_hash_find(const ZixHash* hash, const void* key)
+{
+	const unsigned h     = hash->hash_func(key) % *hash->n_buckets;
+	Entry* const   entry = find_entry(hash, key, h);
+	return entry ? entry->data : 0;
+}
+
+ZixStatus
+zix_hash_insert(ZixHash* hash, const void* key, void* data)
+{
+	unsigned h_nomod = hash->hash_func(key);
+	unsigned h       = h_nomod % *hash->n_buckets;
+
+	Entry* elem = find_entry(hash, key, h);
+	if (elem) {
+		assert(elem->hash == h_nomod);
+		return ZIX_STATUS_EXISTS;
+	}
+
+	elem = (Entry*)malloc(sizeof(Entry));
+	if (!elem) {
+		return ZIX_STATUS_NO_MEM;
+	}
+	elem->key  = key;
+	elem->data = data;
+	elem->next = NULL;
+	elem->hash = h_nomod;
+	const unsigned next_n_buckets = *(hash->n_buckets + 1);
+	if (next_n_buckets != 0 && (hash->count + 1) >= next_n_buckets) {
+		if (!rehash(hash, next_n_buckets)) {
+			h = h_nomod % *(++hash->n_buckets);
+		}
+	}
+
+	insert_entry(&hash->buckets[h], elem);
+	++hash->count;
+	return ZIX_STATUS_SUCCESS;
+}
+
+ZixStatus
+zix_hash_remove(ZixHash* hash, const void* key)
+{
+	unsigned h = hash->hash_func(key) % *hash->n_buckets;
+
+	Entry** next_ptr = &hash->buckets[h];
+	for (Entry* e = hash->buckets[h]; e; e = e->next) {
+		if (hash->key_equal_func(e->key, key)) {
+			*next_ptr = e->next;
+			free(e);
+			return ZIX_STATUS_SUCCESS;
+		}
+		next_ptr = &e->next;
+	}
+
+	if (hash->n_buckets != sizes) {
+		const unsigned prev_n_buckets = *(hash->n_buckets - 1);
+		if (hash->count - 1 <= prev_n_buckets) {
+			if (!rehash(hash, prev_n_buckets)) {
+				--hash->n_buckets;
+			}
+		}
+	}
+
+	--hash->count;
+	return ZIX_STATUS_NOT_FOUND;
+}
+
+ZIX_API
+void
+zix_hash_foreach(const ZixHash* hash,
+                 void (*f)(const void* key, void* value, void* user_data),
+                 void* user_data)
+{
+	for (unsigned b = 0; b < *hash->n_buckets; ++b) {
+		Entry* bucket = hash->buckets[b];
+		for (Entry* e = bucket; e; e = e->next) {
+			f(e->key, e->data, user_data);
+		}
+	}
+}
+
diff --git a/src/zix/hash.h b/src/zix/hash.h
new file mode 100644
index 0000000..44521f1
--- /dev/null
+++ b/src/zix/hash.h
@@ -0,0 +1,75 @@
+/*
+  Copyright 2011 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef ZIX_HASH_H
+#define ZIX_HASH_H
+
+#include "zix/common.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct ZixHashImpl ZixHash;
+
+/**
+   Function for computing the hash of an element.
+*/
+typedef unsigned (*ZixHashFunc)(const void* key);
+
+ZIX_API
+ZixHash*
+zix_hash_new(ZixHashFunc  hash_func,
+             ZixEqualFunc key_equal_func);
+
+ZIX_API
+void
+zix_hash_free(ZixHash* hash);
+
+ZIX_API
+unsigned
+zix_string_hash(const void* key);
+
+ZIX_API
+bool
+zix_string_equal(const void* a, const void* b);
+
+ZIX_API
+ZixStatus
+zix_hash_insert(ZixHash*    hash,
+                const void* key,
+                void*       data);
+
+ZIX_API
+ZixStatus
+zix_hash_remove(ZixHash* hash, const void* key);
+
+ZIX_API
+void*
+zix_hash_find(const ZixHash* hash,
+              const void*    key);
+
+ZIX_API
+void
+zix_hash_foreach(const ZixHash* hash,
+                 void (*f)(const void* key, void* value, void* user_data),
+                 void* user_data);
+
+#ifdef __cplusplus
+}  /* extern "C" */
+#endif
+
+#endif  /* ZIX_HASH_H */
diff --git a/src/zix/tree.c b/src/zix/tree.c
new file mode 100644
index 0000000..30ac3e2
--- /dev/null
+++ b/src/zix/tree.c
@@ -0,0 +1,590 @@
+/*
+  Copyright 2011 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include <assert.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "zix/common.h"
+#include "zix/tree.h"
+
+typedef struct ZixTreeNodeImpl ZixTreeNode;
+
+struct ZixTreeImpl {
+	ZixTreeNode*  root;
+	ZixComparator cmp;
+	void*         cmp_data;
+	bool          allow_duplicates;
+};
+
+struct ZixTreeNodeImpl {
+	void*                   data;
+	struct ZixTreeNodeImpl* left;
+	struct ZixTreeNodeImpl* right;
+	struct ZixTreeNodeImpl* parent;
+	int_fast8_t             balance;
+};
+
+#define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#define MAX(a, b) (((a) > (b)) ? (a) : (b))
+
+ZIX_API
+ZixTree*
+zix_tree_new(bool allow_duplicates, ZixComparator cmp, void* cmp_data)
+{
+	ZixTree* t = malloc(sizeof(ZixTree));
+	t->root             = NULL;
+	t->cmp              = cmp;
+	t->cmp_data         = cmp_data;
+	t->allow_duplicates = allow_duplicates;
+	return t;
+}
+
+static void
+zix_tree_free_rec(ZixTreeNode* n)
+{
+	if (n) {
+		zix_tree_free_rec(n->left);
+		zix_tree_free_rec(n->right);
+		free(n);
+	}
+}
+
+ZIX_API
+void
+zix_tree_free(ZixTree* t)
+{
+	zix_tree_free_rec(t->root);
+
+	free(t);
+}
+
+static void
+rotate(ZixTreeNode* p, ZixTreeNode* q)
+{
+	assert(q->parent == p);
+	assert(p->left == q || p->right == q);
+
+	q->parent = p->parent;
+	if (q->parent) {
+		if (q->parent->left == p) {
+			q->parent->left = q;
+		} else {
+			q->parent->right = q;
+		}
+	}
+
+	if (p->right == q) {
+		// Rotate left
+		p->right = q->left;
+		q->left  = p;
+		if (p->right) {
+			p->right->parent = p;
+		}
+	} else {
+		// Rotate right
+		assert(p->left == q);
+		p->left  = q->right;
+		q->right = p;
+		if (p->left) {
+			p->left->parent = p;
+		}
+	}
+
+	p->parent = q;
+}
+
+/**
+ * Rotate left about @a p.
+ *
+ *    p              q
+ *   / \            / \
+ *  A   q    =>    p   C
+ *     / \        / \
+ *    B   C      A   B
+ */
+static ZixTreeNode*
+rotate_left(ZixTreeNode* p, int* height_change)
+{
+	ZixTreeNode* const q = p->right;
+	*height_change = (q->balance == 0) ? 0 : -1;
+
+	assert(p->balance == 2);
+	assert(q->balance == 0 || q->balance == 1);
+
+	rotate(p, q);
+
+	--q->balance;
+	p->balance = -(q->balance);
+
+	return q;
+}
+
+/**
+ * Rotate right about @a p.
+ *
+ *      p          q
+ *     / \        / \
+ *    q   C  =>  A   p
+ *   / \            / \
+ *  A   B          B   C
+ *
+ */
+static ZixTreeNode*
+rotate_right(ZixTreeNode* p, int* height_change)
+{
+	ZixTreeNode* const q = p->left;
+	*height_change = (q->balance == 0) ? 0 : -1;
+
+	assert(p->balance == -2);
+	assert(q->balance == 0 || q->balance == -1);
+
+	rotate(p, q);
+
+	++q->balance;
+	p->balance = -(q->balance);
+
+	return q;
+}
+
+/**
+ * Rotate left about @a p->left then right about @a p.
+ *
+ *      p             r
+ *     / \           / \
+ *    q   D  =>    q     p
+ *   / \          / \   / \
+ *  A   r        A   B C   D
+ *     / \
+ *    B   C
+ *
+ */
+static ZixTreeNode*
+rotate_left_right(ZixTreeNode* p, int* height_change)
+{
+	ZixTreeNode* const q = p->left;
+	ZixTreeNode* const r = q->right;
+
+	assert(p->balance == -2);
+	assert(q->balance == 1);
+	assert(r->balance == -1 || r->balance == 0 || r->balance == 1);
+
+	rotate(q, r);
+	rotate(p, r);
+
+	q->balance -= 1 + MAX(0, r->balance);
+	p->balance += 1 - MIN(MIN(0, r->balance) - 1, r->balance + q->balance);
+	r->balance = 0;
+
+	*height_change = -1;
+
+	return r;
+}
+
+/**
+ * Rotate right about @a p->right then right about @a p.
+ *
+ *    p               r
+ *   / \             / \
+ *  A   q    =>    p     q
+ *     / \        / \   / \
+ *    r   D      A   B C   D
+ *   / \
+ *  B   C
+ *
+ */
+static ZixTreeNode*
+rotate_right_left(ZixTreeNode* p, int* height_change)
+{
+	ZixTreeNode* const q = p->right;
+	ZixTreeNode* const r = q->left;
+
+	assert(p->balance == 2);
+	assert(q->balance == -1);
+	assert(r->balance == -1 || r->balance == 0 || r->balance == 1);
+
+	rotate(q, r);
+	rotate(p, r);
+
+	q->balance += 1 - MIN(0, r->balance);
+	p->balance -= 1 + MAX(MAX(0, r->balance) + 1, r->balance + q->balance);
+	r->balance = 0;
+
+	*height_change = -1;
+
+	return r;
+}
+
+static ZixTreeNode*
+zix_tree_rebalance(ZixTree* t, ZixTreeNode* node, int* height_change)
+{
+	*height_change = 0;
+	const bool is_root = !node->parent;
+	assert((is_root && t->root == node) || (!is_root && t->root != node));
+	ZixTreeNode* replacement = node;
+	if (node->balance == -2) {
+		assert(node->left);
+		if (node->left->balance == 1) {
+			replacement = rotate_left_right(node, height_change);
+		} else {
+			replacement = rotate_right(node, height_change);
+		}
+	} else if (node->balance == 2) {
+		assert(node->right);
+		if (node->right->balance == -1) {
+			replacement = rotate_right_left(node, height_change);
+		} else {
+			replacement = rotate_left(node, height_change);
+		}
+	}
+	if (is_root) {
+		assert(!replacement->parent);
+		t->root = replacement;
+	}
+
+	return replacement;
+}
+
+ZIX_API
+ZixStatus
+zix_tree_insert(ZixTree* t, void* e, ZixTreeIter** ti)
+{
+	int          cmp = 0;
+	ZixTreeNode* n   = t->root;
+	ZixTreeNode* p   = NULL;
+
+	// Find the parent p of e
+	while (n) {
+		p   = n;
+		cmp = t->cmp(e, n->data, t->cmp_data);
+		if (cmp < 0) {
+			n = n->left;
+		} else if (cmp > 0) {
+			n = n->right;
+		} else if (t->allow_duplicates) {
+			n = n->right;
+		} else {
+			if (ti) {
+				*ti = n;
+			}
+			return ZIX_STATUS_EXISTS;
+		}
+	}
+
+	// Allocate a new node n
+	if (!(n = malloc(sizeof(ZixTreeNode)))) {
+		return ZIX_STATUS_NO_MEM;
+	}
+	memset(n, '\0', sizeof(ZixTreeNode));
+	n->data    = e;
+	n->balance = 0;
+	if (ti) {
+		*ti = n;
+	}
+
+	bool p_height_increased = false;
+
+	// Make p the parent of n
+	n->parent = p;
+	if (!p) {
+		t->root = n;
+	} else {
+		if (cmp < 0) {
+			assert(!p->left);
+			assert(p->balance == 0 || p->balance == 1);
+			p->left = n;
+			--p->balance;
+			p_height_increased = !p->right;
+		} else {
+			assert(!p->right);
+			assert(p->balance == 0 || p->balance == -1);
+			p->right = n;
+			++p->balance;
+			p_height_increased = !p->left;
+		}
+	}
+
+	// Rebalance if necessary (at most 1 rotation)
+	assert(!p || p->balance == -1 || p->balance == 0 || p->balance == 1);
+	if (p && p_height_increased) {
+		int height_change = 0;
+		for (ZixTreeNode* i = p; i && i->parent; i = i->parent) {
+			if (i == i->parent->left) {
+				if (--i->parent->balance == -2) {
+					zix_tree_rebalance(t, i->parent, &height_change);
+					break;
+				}
+			} else {
+				assert(i == i->parent->right);
+				if (++i->parent->balance == 2) {
+					zix_tree_rebalance(t, i->parent, &height_change);
+					break;
+				}
+			}
+
+			if (i->parent->balance == 0) {
+				break;
+			}
+		}
+	}
+
+	return ZIX_STATUS_SUCCESS;
+}
+
+ZIX_API
+ZixStatus
+zix_tree_remove(ZixTree* t, ZixTreeIter* ti)
+{
+	ZixTreeNode* const n          = ti;
+	ZixTreeNode**      pp         = NULL;  // parent pointer
+	ZixTreeNode*       to_balance = n->parent;  // lowest node to balance
+	int8_t             d_balance  = 0;  // delta(balance) for n->parent
+
+	if ((n == t->root) && !n->left && !n->right) {
+		t->root = NULL;
+		free(n);
+		return ZIX_STATUS_SUCCESS;
+	}
+
+	// Set pp to the parent pointer to n, if applicable
+	if (n->parent) {
+		assert(n->parent->left == n || n->parent->right == n);
+		if (n->parent->left == n) {  // n is left child
+			pp        = &n->parent->left;
+			d_balance = 1;
+		} else {  // n is right child
+			assert(n->parent->right == n);
+			pp        = &n->parent->right;
+			d_balance = -1;
+		}
+	}
+
+	assert(!pp || *pp == n);
+
+	int height_change = 0;
+	if (!n->left && !n->right) {
+		// n is a leaf, just remove it
+		if (pp) {
+			*pp           = NULL;
+			to_balance    = n->parent;
+			height_change = (!n->parent->left && !n->parent->right) ? -1 : 0;
+		}
+	} else if (!n->left) {
+		// Replace n with right (only) child
+		if (pp) {
+			*pp        = n->right;
+			to_balance = n->parent;
+		} else {
+			t->root = n->right;
+		}
+		n->right->parent = n->parent;
+		height_change    = -1;
+	} else if (!n->right) {
+		// Replace n with left (only) child
+		if (pp) {
+			*pp        = n->left;
+			to_balance = n->parent;
+		} else {
+			t->root = n->left;
+		}
+		n->left->parent = n->parent;
+		height_change   = -1;
+	} else {
+		// Replace n with in-order successor (leftmost child of right subtree)
+		ZixTreeNode* replace = n->right;
+		while (replace->left) {
+			assert(replace->left->parent == replace);
+			replace = replace->left;
+		}
+
+		// Remove replace from parent (replace_p)
+		if (replace->parent->left == replace) {
+			height_change = replace->parent->right ? 0 : -1;
+			d_balance     = 1;
+			to_balance    = replace->parent;
+			replace->parent->left = replace->right;
+		} else {
+			assert(replace->parent == n);
+			height_change = replace->parent->left ? 0 : -1;
+			d_balance     = -1;
+			to_balance    = replace->parent;
+			replace->parent->right = replace->right;
+		}
+
+		if (to_balance == n) {
+			to_balance = replace;
+		}
+
+		if (replace->right) {
+			replace->right->parent = replace->parent;
+		}
+
+		replace->balance = n->balance;
+
+		// Swap node to delete with replace
+		if (pp) {
+			*pp = replace;
+		} else {
+			assert(t->root == n);
+			t->root = replace;
+		}
+		replace->parent = n->parent;
+		replace->left   = n->left;
+		n->left->parent = replace;
+		replace->right  = n->right;
+		if (n->right) {
+			n->right->parent = replace;
+		}
+
+		assert(!replace->parent
+		       || replace->parent->left == replace
+		       || replace->parent->right == replace);
+	}
+
+	// Rebalance starting at to_balance upwards.
+	for (ZixTreeNode* i = to_balance; i; i = i->parent) {
+		i->balance += d_balance;
+		if (d_balance == 0 || i->balance == -1 || i->balance == 1) {
+			break;
+		}
+
+		assert(i != n);
+		i = zix_tree_rebalance(t, i, &height_change);
+		if (i->balance == 0) {
+			height_change = -1;
+		}
+
+		if (i->parent) {
+			if (i == i->parent->left) {
+				d_balance = height_change * -1;
+			} else {
+				assert(i == i->parent->right);
+				d_balance = height_change;
+			}
+		}
+	}
+
+	free(n);
+
+	return ZIX_STATUS_SUCCESS;
+}
+
+ZIX_API
+ZixStatus
+zix_tree_find(const ZixTree* t, const void* e, ZixTreeIter** ti)
+{
+	ZixTreeNode* n = t->root;
+	while (n) {
+		const int cmp = t->cmp(e, n->data, t->cmp_data);
+		if (cmp == 0) {
+			break;
+		} else if (cmp < 0) {
+			n = n->left;
+		} else {
+			n = n->right;
+		}
+	}
+
+	*ti = n;
+	return (n) ? ZIX_STATUS_SUCCESS : ZIX_STATUS_NOT_FOUND;
+}
+
+ZIX_API
+void*
+zix_tree_get(ZixTreeIter* ti)
+{
+	return ti->data;
+}
+
+ZIX_API
+ZixTreeIter*
+zix_tree_begin(ZixTree* t)
+{
+	if (!t->root) {
+		return NULL;
+	}
+
+	ZixTreeNode* n = t->root;
+	while (n->left) {
+		n = n->left;
+	}
+	return n;
+}
+
+ZIX_API
+ZixTreeIter*
+zix_tree_end(ZixTree* t)
+{
+	return NULL;
+}
+
+ZIX_API
+bool
+zix_tree_iter_is_end(ZixTreeIter* i)
+{
+	return !i;
+}
+
+ZIX_API
+ZixTreeIter*
+zix_tree_iter_next(ZixTreeIter* i)
+{
+	if (!i) {
+		return NULL;
+	}
+
+	if (i->right) {
+		i = i->right;
+		while (i->left) {
+			i = i->left;
+		}
+	} else {
+		while (i->parent && i->parent->right == i) {  // i is a right child
+			i = i->parent;
+		}
+
+		i = i->parent;
+	}
+
+	return i;
+}
+
+ZIX_API
+ZixTreeIter*
+zix_tree_iter_prev(ZixTreeIter* i)
+{
+	if (!i) {
+		return NULL;
+	}
+
+	if (i->left) {
+		i = i->left;
+		while (i->right) {
+			i = i->right;
+		}
+	} else {
+		while (i->parent && i->parent->left == i) {  // i is a left child
+			i = i->parent;
+		}
+
+		i = i->parent;
+	}
+
+	return i;
+}
diff --git a/src/zix/tree.h b/src/zix/tree.h
new file mode 100644
index 0000000..670c437
--- /dev/null
+++ b/src/zix/tree.h
@@ -0,0 +1,121 @@
+/*
+  Copyright 2011 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef ZIX_TREE_H
+#define ZIX_TREE_H
+
+#include <stdbool.h>
+
+#include "zix/common.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+   @addtogroup zix
+   @{
+   @name Tree
+   @{
+*/
+
+/**
+   A balanced binary search tree.
+*/
+typedef struct ZixTreeImpl ZixTree;
+
+/**
+   An iterator over a @ref ZixTree.
+*/
+typedef struct ZixTreeNodeImpl ZixTreeIter;
+
+/**
+   Create a new (empty) tree.
+*/
+ZixTree*
+zix_tree_new(bool allow_duplicates, ZixComparator cmp, void* cmp_data);
+
+/**
+   Free @a t.
+*/
+void
+zix_tree_free(ZixTree* t);
+
+/**
+   Insert the element @a e into @a t and point @a ti at the new element.
+*/
+ZixStatus
+zix_tree_insert(ZixTree* t, void* e, ZixTreeIter** ti);
+
+/**
+   Remove the item pointed at by @a ti from @a t.
+*/
+ZixStatus
+zix_tree_remove(ZixTree* t, ZixTreeIter* ti);
+
+/**
+   Set @a ti to an element equal to @a e in @a t.
+   If no such item exists, @a ti is set to NULL.
+*/
+ZixStatus
+zix_tree_find(const ZixTree* t, const void* e, ZixTreeIter** ti);
+
+/**
+   Return the data associated with the given tree item.
+*/
+void*
+zix_tree_get(ZixTreeIter* ti);
+
+/**
+   Return an iterator to the first (smallest) element in @a t.
+*/
+ZixTreeIter*
+zix_tree_begin(ZixTree* t);
+
+/**
+   Return an iterator the the element one past the last element in @a t.
+*/
+ZixTreeIter*
+zix_tree_end(ZixTree* t);
+
+/**
+   Return true iff @a i is an iterator to the end of its tree.
+*/
+bool
+zix_tree_iter_is_end(ZixTreeIter* i);
+
+/**
+   Return an iterator that points to the element one past @a i.
+*/
+ZixTreeIter*
+zix_tree_iter_next(ZixTreeIter* i);
+
+/**
+   Return an iterator that points to the element one before @a i.
+*/
+ZixTreeIter*
+zix_tree_iter_prev(ZixTreeIter* i);
+
+/**
+   @}
+   @}
+*/
+
+#ifdef __cplusplus
+}  /* extern "C" */
+#endif
+
+#endif  /* ZIX_TREE_H */