Add interval tree

9 files changed, 1515 insertions, 0 deletions

diff --git a/deps/interval_tree/CMakeLists.txt b/deps/interval_tree/CMakeLists.txt
new file mode 100644
index 0000000..7a6de00
--- /dev/null
+++ b/deps/interval_tree/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_library(interval_tree STATIC interval.cpp interval_list.cpp itree.cpp)
+target_include_directories(interval_tree PUBLIC ${CMAKE_CURRENT_LIST_DIR})
+
+add_subdirectory(test)
\ No newline at end of file
diff --git a/deps/interval_tree/interval.cpp b/deps/interval_tree/interval.cpp
new file mode 100644
index 0000000..bdcebaa
--- /dev/null
+++ b/deps/interval_tree/interval.cpp
@@ -0,0 +1,71 @@
+/*
+ * Libitree: an interval tree library in C
+ *
+ * Copyright (C) 2018 Alessandro Vullo
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "interval.h"
+
+#include <stdlib.h>
+
+interval_t *interval_new(uint64_t low, uint64_t high, void *data, dup_f dup, rel_f rel)
+{
+  interval_t *ri = (interval_t *)malloc(sizeof *ri);
+  if (ri == NULL)
+  {
+    return NULL;
+  }
+
+  ri->low = low;
+  ri->high = high;
+  ri->dup = dup;
+  ri->rel = rel;
+  ri->data = ri->dup(data);
+
+  return ri;
+}
+
+interval_t *interval_copy(const interval_t *i)
+{
+  return interval_new(i->low, i->high, i->data, i->dup, i->rel);
+}
+
+void interval_delete(interval_t *i)
+{
+  if (i != NULL)
+  {
+    if (i->data)
+    {
+      i->rel(i->data);
+    }
+    free(i);
+  }
+}
+
+int interval_overlap(const interval_t *i1, const interval_t *i2)
+{
+  return i1->low <= i2->high && i2->low <= i1->high;
+}
+
+int interval_equal(const interval_t *i1, const interval_t *i2)
+{
+  return i1->low == i2->low && i1->high == i2->high;
+}
diff --git a/deps/interval_tree/interval.h b/deps/interval_tree/interval.h
new file mode 100644
index 0000000..4504c7c
--- /dev/null
+++ b/deps/interval_tree/interval.h
@@ -0,0 +1,59 @@
+/*
+ * Libitree: an interval tree library in C
+ *
+ * Copyright (C) 2018 Alessandro Vullo
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef _INTERVAL_H_
+#define _INTERVAL_H_
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#include <stddef.h>
+#include <stdint.h>
+
+/* User-defined item handling */
+typedef void *(*dup_f)(void *p);
+typedef void (*rel_f)(void *p);
+
+typedef struct interval
+{
+  uint64_t low, high; /* Interval boundaries, inclusive */
+  void *data;      /* User-defined content */
+  dup_f dup;       /* Clone an interval data item */
+  rel_f rel;       /* Destroy an interval data item */
+} interval_t;
+
+/* Interval functions */
+interval_t *interval_new(uint64_t low, uint64_t high, void *data, dup_f dup, rel_f rel);
+interval_t *interval_copy(const interval_t *i);
+void interval_delete(interval_t *i);
+int interval_overlap(const interval_t *i1, const interval_t *i2);
+int interval_equal(const interval_t *i1, const interval_t *i2);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _INTERVAL_H_ */
diff --git a/deps/interval_tree/interval_list.cpp b/deps/interval_tree/interval_list.cpp
new file mode 100644
index 0000000..6700564
--- /dev/null
+++ b/deps/interval_tree/interval_list.cpp
@@ -0,0 +1,277 @@
+/*
+ * Libitree: an interval tree library in C
+ *
+ * Copyright (C) 2018 Alessandro Vullo
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "interval_list.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#ifndef HEIGHT_LIMIT
+#define HEIGHT_LIMIT 64
+#endif
+
+/* Note: doesn't own the interval, comes from the tree
+   which is responsible for deallocating the interval. */
+typedef struct ilistnode
+{
+  const interval_t *interval;
+  struct ilistnode *next;
+} ilistnode_t;
+
+struct ilist
+{
+  ilistnode_t *head, *tail; /* Dummy nodes */
+  size_t size;
+};
+
+struct ilisttrav
+{
+  ilist_t *list;   /* Paired list */
+  ilistnode_t *it; /* Current node */
+};
+
+static ilistnode_t *ilistnode_new(const interval_t *i, ilistnode_t *next)
+{
+  ilistnode_t *node = (ilistnode_t *)malloc(sizeof *node);
+  if (node != NULL)
+  {
+    node->interval = i; /* NOTE: doesn't own the interval, pointer aliasing */
+    node->next = next;
+  }
+
+  return node;
+}
+
+/*
+   Destroy a single node, assuming it's been unlinked.
+   Returns the next node specified by the link.
+*/
+ilistnode_t *ilistnode_delete(ilistnode_t *node)
+{
+  ilistnode_t *next = NULL;
+  if (node != NULL)
+  {
+    /* Save a reference to the next node
+       since we're about to destroy this one */
+    next = node->next;
+    free(node);
+  }
+
+  return next;
+}
+
+ilist_t *ilist_new()
+{
+  ilist_t *list = (ilist_t *)malloc(sizeof *list);
+  if (list != NULL)
+  {
+    ilistnode_t *tail = ilistnode_new(NULL, NULL);
+    if (tail == NULL)
+    {
+      free(list);
+      list = NULL;
+    }
+    else
+    {
+      list->tail = tail;
+      list->head = ilistnode_new(NULL, list->tail);
+
+      if (list->head == NULL)
+      {
+        free(list);
+        list = NULL;
+      }
+      list->size = 0;
+    }
+  }
+
+  return list;
+}
+
+void ilist_delete(ilist_t *list)
+{
+  if (list == NULL)
+  {
+    return;
+  }
+
+  ilistnode_t *it = list->head;
+  while (it != list->tail)
+  {
+    it = ilistnode_delete(it);
+  }
+
+  ilistnode_delete(it); /* Delete tail */
+  free(list);
+}
+
+size_t ilist_size(ilist_t *list)
+{
+  return list->size;
+}
+
+static ilistnode_t *insert_before(ilist_t *, ilistnode_t *, interval_t *);
+static ilistnode_t *insert_after(ilist_t *list, ilistnode_t *pos, interval_t *i)
+{
+  ilistnode_t *node = NULL;
+  if (list != NULL && pos != NULL)
+  {
+    if (pos != list->tail)
+    {
+      node = ilistnode_new(i, pos->next);
+      if (node != NULL)
+      {
+        pos->next = node;
+        ++list->size;
+      }
+    }
+    else
+    {
+      node = insert_before(list, pos, i);
+    }
+  }
+
+  return node;
+}
+
+static ilistnode_t *insert_before(ilist_t *list, ilistnode_t *pos, interval_t *i)
+{
+  ilistnode_t *node = NULL;
+  if (list != NULL && pos != NULL)
+  {
+    if (pos != list->head)
+    {
+      /* Find the previous node */
+      ilistnode_t *it = list->head;
+      while (it->next != pos)
+      {
+        it = it->next;
+      }
+
+      /* Create a new node and set the new link */
+      node = ilistnode_new(i, it->next);
+      if (node != NULL)
+      {
+        it->next = node;
+        ++list->size;
+      }
+    }
+    else
+    {
+      node = insert_after(list, pos, i);
+    }
+  }
+
+  return node;
+}
+
+int ilist_append(ilist_t *list, interval_t *i)
+{
+
+  ilistnode_t *node = insert_before(list, list->tail, i);
+  if (node != NULL)
+  {
+    return 1;
+  }
+
+  return 0;
+}
+
+ilisttrav_t *ilisttrav_new(ilist_t *list)
+{
+  if (list == NULL)
+  {
+    return NULL;
+  }
+
+  ilisttrav_t *trav = (ilisttrav_t *)malloc(sizeof(ilisttrav_t));
+  if (trav != NULL)
+  {
+    trav->list = list;
+  }
+
+  return trav;
+}
+
+void ilisttrav_delete(ilisttrav_t *trav)
+{
+  free(trav);
+}
+
+const interval_t *ilisttrav_first(ilisttrav_t *trav)
+{
+  if (trav->list == NULL)
+  {
+    return NULL;
+  }
+
+  trav->it = trav->list->head->next;
+
+  return trav->it == NULL || trav->it == trav->list->tail ? NULL : trav->it->interval;
+}
+
+const interval_t *ilisttrav_last(ilisttrav_t *trav)
+{
+  if (trav->list == NULL)
+  {
+    return NULL;
+  }
+
+  trav->it = trav->list->head;
+  while (trav->it->next != trav->list->tail)
+  {
+    trav->it = trav->it->next;
+  }
+
+  return trav->it == trav->list->head || trav->it == NULL ? NULL : trav->it->interval;
+}
+
+const interval_t *ilisttrav_next(ilisttrav_t *trav)
+{
+  if (trav == NULL)
+  {
+    return NULL;
+  }
+
+  trav->it = trav->it->next;
+  return trav->it == NULL || trav->it == trav->list->tail ? NULL : trav->it->interval;
+}
+
+/* Very inefficient, need a doubly linked list to properly support this */
+const interval_t *ilisttrav_prev(ilisttrav_t *trav)
+{
+  if (trav == NULL)
+  {
+    return NULL;
+  }
+
+  ilistnode_t *it = trav->list->head;
+  while (it->next != trav->it)
+  {
+    it = it->next;
+  }
+
+  trav->it = it;
+  return trav->it == trav->list->head || trav->it == NULL ? NULL : trav->it->interval;
+}
diff --git a/deps/interval_tree/interval_list.h b/deps/interval_tree/interval_list.h
new file mode 100644
index 0000000..7333419
--- /dev/null
+++ b/deps/interval_tree/interval_list.h
@@ -0,0 +1,57 @@
+/*
+ * Libitree: an interval tree library in C
+ *
+ * Copyright (C) 2018 Alessandro Vullo
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef _INTERVAL_LIST_H_
+#define _INTERVAL_LIST_H_
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#include "interval.h"
+
+/* Declarations for an interval list, opaque types */
+typedef struct ilist ilist_t;
+typedef struct ilisttrav ilisttrav_t;
+
+/* Interval list functions */
+ilist_t *ilist_new();
+void ilist_delete(ilist_t *list);
+size_t ilist_size(ilist_t *list);
+int ilist_append(ilist_t *list, interval_t *i);
+
+/* Interval list traversal functions */
+ilisttrav_t *ilisttrav_new(ilist_t *list);
+void ilisttrav_delete(ilisttrav_t *trav);
+const interval_t *ilisttrav_first(ilisttrav_t *trav);
+const interval_t *ilisttrav_last(ilisttrav_t *trav);
+const interval_t *ilisttrav_next(ilisttrav_t *trav);
+const interval_t *ilisttrav_prev(ilisttrav_t *trav);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _INTERVAL_LIST_H_ */
diff --git a/deps/interval_tree/itree.cpp b/deps/interval_tree/itree.cpp
new file mode 100644
index 0000000..5bb68ef
--- /dev/null
+++ b/deps/interval_tree/itree.cpp
@@ -0,0 +1,629 @@
+/*
+ * Libitree: an interval tree library in C
+ *
+ * Copyright (C) 2018 Alessandro Vullo
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/*
+  Interval Tree library
+
+  This is an adaptation of the AVL balanced tree C library
+  created by Julienne Walker which can be found here:
+
+  http://www.eternallyconfuzzled.com/Libraries.aspx
+
+*/
+
+#include "itree.h"
+
+#include <stdlib.h>
+
+#ifndef HEIGHT_LIMIT
+#define HEIGHT_LIMIT 64 /* Tallest allowable tree */
+#endif
+
+typedef struct itreenode
+{
+  int balance;               /* Balance factor */
+  uint64_t max;              /* Maximum high value in the subtree rooted at this node */
+  interval_t *interval;      /* The interval the node represents */
+  struct itreenode *link[2]; /* Left (0) and right (1) links */
+} itreenode_t;
+
+struct itree
+{
+  itreenode_t *root; /* Top of the tree */
+  dup_f dup;         /* Clone an interval data item (user-defined) */
+  rel_f rel;         /* Destroy an interval data item (user-defined) */
+  size_t size;       /* Number of items (user-defined) */
+};
+
+struct itreetrav
+{
+  itree_t *tree;                   /* Paired tree */
+  itreenode_t *it;                 /* Current node */
+  itreenode_t *path[HEIGHT_LIMIT]; /* Traversal path */
+  size_t top;                      /* Top of stack */
+};
+
+/* Two way single rotation */
+#define single(root, dir)                 \
+  do                                      \
+  {                                       \
+    itreenode_t *save = root->link[!dir]; \
+    root->link[!dir] = save->link[dir];   \
+    save->link[dir] = root;               \
+    root = save;                          \
+  } while (0)
+
+/* Two way double rotation */
+#define double(root, dir)                            \
+  do                                                 \
+  {                                                  \
+    itreenode_t *save = root->link[!dir]->link[dir]; \
+    root->link[!dir]->link[dir] = save->link[!dir];  \
+    save->link[!dir] = root->link[!dir];             \
+    root->link[!dir] = save;                         \
+    save = root->link[!dir];                         \
+    root->link[!dir] = save->link[dir];              \
+    save->link[dir] = root;                          \
+    root = save;                                     \
+  } while (0)
+
+/* Adjust balance before double rotation */
+#define adjust_balance(root, dir, bal) \
+  do                                   \
+  {                                    \
+    itreenode_t *n = root->link[dir];  \
+    itreenode_t *nn = n->link[!dir];   \
+    if (nn->balance == 0)              \
+    {                                  \
+      root->balance = n->balance = 0;  \
+    }                                  \
+    else if (nn->balance == bal)       \
+    {                                  \
+      root->balance = -bal;            \
+      n->balance = 0;                  \
+    }                                  \
+    else                               \
+    { /* nn->balance == -bal */        \
+      root->balance = 0;               \
+      n->balance = bal;                \
+    }                                  \
+    nn->balance = 0;                   \
+  } while (0)
+
+/* Rebalance after insertion */
+#define insert_balance(root, dir)     \
+  do                                  \
+  {                                   \
+    itreenode_t *n = root->link[dir]; \
+    int bal = dir == 0 ? -1 : +1;     \
+    if (n->balance == bal)            \
+    {                                 \
+      root->balance = n->balance = 0; \
+      single(root, !dir);             \
+    }                                 \
+    else                              \
+    { /* n->balance == -bal */        \
+      adjust_balance(root, dir, bal); \
+      double(root, !dir);             \
+    }                                 \
+  } while (0)
+
+/* Rebalance after deletion */
+#define remove_balance(root, dir, done) \
+  do                                    \
+  {                                     \
+    itreenode_t *n = root->link[!dir];  \
+    int bal = dir == 0 ? -1 : +1;       \
+    if (n->balance == -bal)             \
+    {                                   \
+      root->balance = n->balance = 0;   \
+      single(root, dir);                \
+    }                                   \
+    else if (n->balance == bal)         \
+    {                                   \
+      adjust_balance(root, !dir, -bal); \
+      double(root, dir);                \
+    }                                   \
+    else                                \
+    { /* n->balance == 0 */             \
+      root->balance = -bal;             \
+      n->balance = bal;                 \
+      single(root, dir);                \
+      done = 1;                         \
+    }                                   \
+  } while (0)
+
+static itreenode_t *new_node(itree_t *tree, interval_t *i)
+{
+  itreenode_t *rn = (itreenode_t *)malloc(sizeof *rn);
+  if (rn == NULL)
+  {
+    return NULL;
+  }
+
+  rn->interval = (interval_t *)malloc(sizeof(interval_t));
+  if (rn->interval == NULL)
+  {
+    return NULL;
+  }
+
+  rn->interval->low = i->low;
+  rn->interval->high = i->high;
+  rn->interval->data = tree->dup(i->data);
+
+  rn->balance = 0;
+  rn->max = i->high;
+  rn->link[0] = rn->link[1] = NULL;
+
+  return rn;
+}
+
+itree_t *itree_new(dup_f dup, rel_f rel)
+{
+  itree_t *rt = (itree_t *)malloc(sizeof *rt);
+  if (rt == NULL)
+  {
+    return NULL;
+  }
+
+  rt->root = NULL;
+  rt->dup = dup;
+  rt->rel = rel;
+  rt->size = 0;
+
+  return rt;
+}
+
+void itree_delete(itree_t *tree)
+{
+  itreenode_t *it = tree->root;
+  itreenode_t *save;
+
+  /* Destruction by rotation */
+  while (it != NULL)
+  {
+    if (it->link[0] == NULL)
+    {
+      /* Remove node */
+      save = it->link[1];
+      tree->rel(it->interval->data);
+      free(it->interval);
+      free(it);
+    }
+    else
+    {
+      /* Rotate right */
+      save = it->link[0];
+      it->link[0] = save->link[1];
+      save->link[1] = it;
+    }
+
+    it = save;
+  }
+
+  free(tree);
+}
+
+interval_t *itree_find(itree_t *tree, interval_t *interval)
+{
+  itreenode_t *it = tree->root;
+  while (it != NULL)
+  {
+    /* int cmp = tree->cmp ( it->data, data ); */
+
+    /* if ( cmp == 0 ) */
+    /*   break; */
+
+    /* it = it->link[cmp < 0]; */
+
+    if (interval_overlap(it->interval, interval))
+    {
+      break;
+    }
+
+    it = it->link[it->link[0] == NULL || it->link[0]->max < interval->low];
+  }
+
+  return it == NULL ? NULL : it->interval;
+}
+
+void search(itreenode_t *node, interval_t *interval, ilist_t *results)
+{
+  /*
+   * If interval is to the right of the rightmost point of any interval
+   * in this node and all its children, there won't be any matches
+   */
+  if (node == NULL || interval->low > node->max)
+  {
+    return;
+  }
+
+  /* search the left subtree */
+  if (node->link[0] != NULL && node->link[0]->max >= interval->low)
+  {
+    search(node->link[0], interval, results);
+  }
+
+  /* search this node */
+  if (interval_overlap(node->interval, interval))
+  {
+    ilist_append(results, node->interval);
+  }
+
+  /*
+   * if interval is to the left of the start of this interval
+   * it can't be in any child to the right
+   */
+  if (interval->high < node->interval->low)
+  {
+    return;
+  }
+
+  /* search the right subtree */
+  search(node->link[1], interval, results);
+}
+
+ilist_t *itree_findall(itree_t *tree, interval_t *interval)
+{
+  ilist_t *results = ilist_new();
+  if (results != NULL)
+  {
+    /* empty tree case */
+    if (tree->root == NULL)
+    {
+      return results;
+    }
+
+    search(tree->root, interval, results);
+  }
+
+  return results;
+}
+
+int itree_insert(itree_t *tree, interval_t *interval)
+{
+  /* Empty tree case */
+  if (tree->root == NULL)
+  {
+    tree->root = new_node(tree, interval);
+    if (tree->root == NULL)
+    {
+      return 0;
+    }
+  }
+  else
+  {
+    itreenode_t head = {0}; /* Temporary tree root */
+    itreenode_t *s, *t;     /* Place to rebalance and parent */
+    itreenode_t *p, *q;     /* Iterator and save pointer to the newly inserted node */
+    int dir;
+
+    /* Set up false root to ease maintenance */
+    t = &head;
+    t->link[1] = tree->root;
+
+    /* Search down the tree, saving rebalance points */
+    for (s = p = t->link[1];; p = q)
+    {
+      /* Duplicates admitted, placed in the right subtree */
+      dir = p->interval->low <= interval->low; /* tree->cmp ( p->data, data ) < 0; */
+      q = p->link[dir];
+
+      p->max = p->max < interval->high ? interval->high : p->max; /* Update ancestor's max if needed */
+
+      if (q == NULL)
+      {
+        break;
+      }
+
+      if (q->balance != 0)
+      {
+        t = p;
+        s = q;
+      }
+    }
+
+    p->link[dir] = q = new_node(tree, interval);
+    if (q == NULL)
+    {
+      return 0; /* TODO: should rollback to previous ancestors' max values */
+    }
+
+    /* Update balance factors */
+    for (p = s; p != q; p = p->link[dir])
+    {
+      dir = p->interval->low <= interval->low; /* tree->cmp ( p->data, data ) < 0; */
+      p->balance += dir == 0 ? -1 : +1;
+    }
+
+    q = s; /* Save rebalance point for parent fix */
+
+    /* Rebalance if necessary */
+    if (abs(s->balance) > 1)
+    {
+      dir = s->interval->low <= interval->low; /* tree->cmp ( s->data, data ) < 0; */
+      insert_balance(s, dir);
+    }
+
+    /* Fix parent */
+    if (q == head.link[1])
+    {
+      tree->root = s;
+    }
+    else
+    {
+      t->link[q == t->link[1]] = s;
+    }
+  }
+
+  ++tree->size;
+
+  return 1;
+}
+
+int itree_remove(itree_t *tree, interval_t *interval)
+{
+  if (tree->root != NULL)
+  {
+    itreenode_t *it, *up[HEIGHT_LIMIT];
+    int upd[HEIGHT_LIMIT], top = 0, top_max;
+    int done = 0;
+
+    it = tree->root;
+
+    /* Search down tree and save path */
+    for (;;)
+    {
+      if (it == NULL)
+      {
+        return 0;
+      }
+      // else if (interval_equal(it->interval, interval))
+      else if (it->interval->low >= interval->low && it->interval->high <= interval->high)
+      {
+        break;
+      }
+
+      /* Push direction and node onto stack */
+      upd[top] = it->interval->low <= interval->low; /* tree->cmp ( it->data, data ) < 0; */
+      up[top++] = it;
+
+      it = it->link[upd[top - 1]];
+    }
+
+    /* Remove the node */
+    if (it->link[0] == NULL || it->link[1] == NULL)
+    {
+      /* Which child is not null? */
+      int dir = it->link[0] == NULL;
+
+      /* Fix parent */
+      if (top != 0)
+      {
+        up[top - 1]->link[upd[top - 1]] = it->link[dir];
+      }
+      else
+      {
+        tree->root = it->link[dir];
+      }
+
+      tree->rel(it->interval->data);
+      free(it->interval);
+      free(it);
+    }
+    else
+    {
+      /* Find the inorder successor */
+      itreenode_t *heir = it->link[1];
+      void *save;
+
+      /* Save this path too */
+      upd[top] = 1;
+      up[top++] = it;
+
+      while (heir->link[0] != NULL)
+      {
+        upd[top] = 0;
+        up[top++] = heir;
+        heir = heir->link[0];
+      }
+
+      /* Swap data */
+      save = it->interval;
+      it->interval = heir->interval;
+      heir->interval = (interval_t *)save;
+
+      /* Unlink successor and fix parent */
+      up[top - 1]->link[up[top - 1] == it] = heir->link[1];
+
+      tree->rel(heir->interval->data);
+      free(heir->interval);
+      free(heir);
+    }
+
+    /* Update max: walk back up the search path and bubbles up to root */
+    top_max = top;
+
+    while (--top_max >= 0)
+    {
+      itreenode_t *left = up[top_max]->link[0], *right = up[top_max]->link[1];
+      if (left != NULL && right != NULL)
+      {
+        uint64_t left_right_max = left->max < right->max ? right->max : left->max;
+        up[top_max]->max = up[top_max]->interval->high < left_right_max ? left_right_max : up[top_max]->interval->high;
+      }
+      else if (left != NULL && right == NULL)
+      {
+        up[top_max]->max = up[top_max]->interval->high < left->max ? left->max : up[top_max]->interval->high;
+      }
+      else if (left == NULL && right != NULL)
+      {
+        up[top_max]->max = up[top_max]->interval->high < right->max ? right->max : up[top_max]->interval->high;
+      }
+      else
+      {
+        up[top_max]->max = up[top_max]->interval->high;
+      }
+    }
+
+    /* Walk back up the search path */
+    while (--top >= 0 && !done)
+    {
+      /* Update balance factors */
+      up[top]->balance += upd[top] != 0 ? -1 : +1;
+
+      /* Terminate or rebalance as necessary */
+      if (abs(up[top]->balance) == 1)
+      {
+        break;
+      }
+      else if (abs(up[top]->balance) > 1)
+      {
+        remove_balance(up[top], upd[top], done);
+
+        /* Fix parent */
+        if (top != 0)
+        {
+          up[top - 1]->link[upd[top - 1]] = up[top];
+        }
+        else
+        {
+          tree->root = up[0];
+        }
+      }
+    }
+
+    --tree->size;
+  }
+
+  return 1;
+}
+
+size_t itree_size(itree_t *tree)
+{
+  return tree->size;
+}
+
+itreetrav_t *itreetnew(void)
+{
+  return (itreetrav_t *)malloc(sizeof(itreetrav_t));
+}
+
+void itreetdelete(itreetrav_t *trav)
+{
+  free(trav);
+}
+
+/*
+  First step in traversal,
+  handles min and max
+*/
+static interval_t *start(itreetrav_t *trav, itree_t *tree, int dir)
+{
+  trav->tree = tree;
+  trav->it = tree->root;
+  trav->top = 0;
+
+  /* Build a path to work with */
+  if (trav->it != NULL)
+  {
+    while (trav->it->link[dir] != NULL)
+    {
+      trav->path[trav->top++] = trav->it;
+      trav->it = trav->it->link[dir];
+    }
+  }
+
+#ifdef DEBUG
+  if (trav->it)
+    printf("[%.1f, %.1f] (%d) (%.1f)\n", trav->it->interval->low, trav->it->interval->high, *(int *)trav->it->interval->data, trav->it->max);
+#endif
+
+  return trav->it == NULL ? NULL : trav->it->interval;
+}
+
+/*
+  Subsequent traversal steps,
+  handles ascending and descending
+*/
+static interval_t *move(itreetrav_t *trav, int dir)
+{
+  if (trav->it->link[dir] != NULL)
+  {
+    /* Continue down this branch */
+    trav->path[trav->top++] = trav->it;
+    trav->it = trav->it->link[dir];
+
+    while (trav->it->link[!dir] != NULL)
+    {
+      trav->path[trav->top++] = trav->it;
+      trav->it = trav->it->link[!dir];
+    }
+  }
+  else
+  {
+    /* Move to the next branch */
+    itreenode_t *last;
+    do
+    {
+      if (trav->top == 0)
+      {
+        trav->it = NULL;
+        {
+          break;
+        }
+      }
+
+      last = trav->it;
+      trav->it = trav->path[--trav->top];
+    } while (last == trav->it->link[dir]);
+  }
+
+#ifdef DEBUG
+  if (trav->it)
+    printf("[%.1f, %.1f] (%d) (%.1f)\n", trav->it->interval->low, trav->it->interval->high, *(int *)trav->it->interval->data, trav->it->max);
+#endif
+
+  return trav->it == NULL ? NULL : trav->it->interval;
+}
+
+interval_t *itreetfirst(itreetrav_t *trav, itree_t *tree)
+{
+  return start(trav, tree, 0); /* Min value */
+}
+
+interval_t *itreetlast(itreetrav_t *trav, itree_t *tree)
+{
+  return start(trav, tree, 1); /* Max value */
+}
+
+interval_t *itreetnext(itreetrav_t *trav)
+{
+  return move(trav, 1); /* Toward larger items */
+}
+
+interval_t *itreetprev(itreetrav_t *trav)
+{
+  return move(trav, 0); /* Toward smaller items */
+}
diff --git a/deps/interval_tree/itree.h b/deps/interval_tree/itree.h
new file mode 100644
index 0000000..505e272
--- /dev/null
+++ b/deps/interval_tree/itree.h
@@ -0,0 +1,77 @@
+/*
+ * Libitree: an interval tree library in C
+ *
+ * Copyright (C) 2018 Alessandro Vullo
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef _INTERVAL_TREE_H_
+#define _INTERVAL_TREE_H_
+
+/*
+  Interval Tree library
+
+  This is an adaptation of the AVL balanced tree C library
+  created by Julienne Walker which can be found here:
+
+  http://www.eternallyconfuzzled.com/Libraries.aspx
+
+*/
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#include "interval.h"
+#include "interval_list.h"
+
+/* Opaque types */
+typedef struct itree itree_t;
+typedef struct itreetrav itreetrav_t;
+
+/* User-defined interval data item handling */
+typedef void *(*dup_f)(void *p);
+typedef void (*rel_f)(void *p);
+
+/* Interval tree functions */
+itree_t *itree_new(dup_f dup, rel_f rel);
+void itree_delete(itree_t *tree);
+// Find the first interval containing the specified interval
+interval_t *itree_find(itree_t *tree, interval_t *interval);
+ilist_t *itree_findall(itree_t *tree, interval_t *interval);
+int itree_insert(itree_t *tree, interval_t *interval);
+// Delete the first interval contained by the specified interval
+int itree_remove(itree_t *tree, interval_t *interval);
+size_t itree_size(itree_t *tree);
+
+/* Tree traversal functions */
+itreetrav_t *itreetnew(void);
+void itreetdelete(itreetrav_t *trav);
+interval_t *itreetfirst(itreetrav_t *trav, itree_t *tree);
+interval_t *itreetlast(itreetrav_t *trav, itree_t *tree);
+interval_t *itreetnext(itreetrav_t *trav);
+interval_t *itreetprev(itreetrav_t *trav);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _INTERVAL_TREE_H_ */
diff --git a/deps/interval_tree/test/CMakeLists.txt b/deps/interval_tree/test/CMakeLists.txt
new file mode 100644
index 0000000..c56eea6
--- /dev/null
+++ b/deps/interval_tree/test/CMakeLists.txt
@@ -0,0 +1,5 @@
+add_executable(gtest_interval_tree gtest_interval_tree.cpp)
+target_link_libraries(gtest_interval_tree interval_tree gtest)
+
+include(GoogleTest)
+gtest_discover_tests(gtest_interval_tree)
\ No newline at end of file
diff --git a/deps/interval_tree/test/gtest_interval_tree.cpp b/deps/interval_tree/test/gtest_interval_tree.cpp
new file mode 100644
index 0000000..417c275
--- /dev/null
+++ b/deps/interval_tree/test/gtest_interval_tree.cpp
@@ -0,0 +1,336 @@
+#include <gtest/gtest.h>
+
+#include "itree.h"
+
+void *my_dup(void *p)
+{
+    return p ? strdup((const char *)p) : NULL;
+}
+
+void my_rel(void *p)
+{
+    if (p)
+    {
+        free(p);
+    }
+}
+
+// find overlap
+#if 1
+TEST(INTERVAL_TREE, FIND)
+{
+    itree_t *tree;
+    interval_t *result;
+    interval_t query;
+    interval_t segment;
+
+    // new
+    tree = itree_new(my_dup, my_rel);
+    EXPECT_TRUE(tree != nullptr);
+    EXPECT_TRUE(itree_size(tree) == 0);
+
+    // insert
+    segment = {
+        .low = 5,
+        .high = 9,
+        .data = (void *)"Hello",
+    };
+    EXPECT_TRUE(itree_insert(tree, &segment) == 1);
+    EXPECT_TRUE(itree_size(tree) == 1);
+
+    // find
+    query = {
+        .low = 5,
+        .high = 5,
+    };
+    result = itree_find(tree, &query);
+    EXPECT_TRUE(result != nullptr);
+    EXPECT_TRUE(result->low == 5);
+    EXPECT_TRUE(result->high == 9);
+    EXPECT_STREQ((const char *)result->data, "Hello");
+
+    // find
+    query = {
+        .low = 6,
+        .high = 8,
+    };
+    result = itree_find(tree, &query);
+    EXPECT_TRUE(result != nullptr);
+    EXPECT_TRUE(result->low == 5);
+    EXPECT_TRUE(result->high == 9);
+    EXPECT_STREQ((const char *)result->data, "Hello");
+
+    // find
+    query = {
+        .low = 5,
+        .high = 9,
+    };
+    result = itree_find(tree, &query);
+    EXPECT_TRUE(result != nullptr);
+    EXPECT_TRUE(result->low == 5);
+    EXPECT_TRUE(result->high == 9);
+    EXPECT_STREQ((const char *)result->data, "Hello");
+
+    // find
+    query = {
+        .low = 9,
+        .high = 9,
+    };
+    result = itree_find(tree, &query);
+    EXPECT_TRUE(result != nullptr);
+    EXPECT_TRUE(result->low == 5);
+    EXPECT_TRUE(result->high == 9);
+    EXPECT_STREQ((const char *)result->data, "Hello");
+
+    // find
+    query = {
+        .low = 1,
+        .high = 14,
+    };
+    result = itree_find(tree, &query);
+    EXPECT_TRUE(result != nullptr);
+    EXPECT_TRUE(result->low == 5);
+    EXPECT_TRUE(result->high == 9);
+    EXPECT_STREQ((const char *)result->data, "Hello");
+
+    // not found
+    query = {
+        .low = 1,
+        .high = 4,
+    };
+    result = itree_find(tree, &query);
+    EXPECT_TRUE(result == nullptr);
+
+    // not found
+    query = {
+        .low = 10,
+        .high = 14,
+    };
+    result = itree_find(tree, &query);
+
+    itree_delete(tree);
+}
+#endif
+
+#if 1
+TEST(INTERVAL_TREE, DELETE1)
+{
+    itree_t *tree;
+    interval_t query;
+    interval_t segment;
+
+    // new
+    tree = itree_new(my_dup, my_rel);
+    EXPECT_TRUE(tree != nullptr);
+    EXPECT_TRUE(itree_size(tree) == 0);
+
+    // insert
+    segment = {
+        .low = 5,
+        .high = 9,
+        .data = (void *)"Hello",
+    };
+    EXPECT_TRUE(itree_insert(tree, &segment) == 1);
+    EXPECT_TRUE(itree_size(tree) == 1);
+
+    // delete
+    query = {
+        .low = 5,
+        .high = 5,
+    };
+    EXPECT_TRUE(itree_remove(tree, &query) == 0);
+    EXPECT_TRUE(itree_size(tree) == 1);
+
+    // delete
+    query = {
+        .low = 9,
+        .high = 9,
+    };
+    EXPECT_TRUE(itree_remove(tree, &query) == 0);
+    EXPECT_TRUE(itree_size(tree) == 1);
+
+    // delete
+    query = {
+        .low = 5,
+        .high = 9,
+    };
+    EXPECT_TRUE(itree_remove(tree, &query) == 1);
+    EXPECT_TRUE(itree_size(tree) == 0);
+
+    itree_delete(tree);
+}
+#endif
+
+#if 1
+TEST(INTERVAL_TREE, DELETE2)
+{
+    itree_t *tree;
+    interval_t query;
+    interval_t segment;
+
+    // new
+    tree = itree_new(my_dup, my_rel);
+    EXPECT_TRUE(tree != nullptr);
+    EXPECT_TRUE(itree_size(tree) == 0);
+
+    // insert
+    segment = {
+        .low = 5,
+        .high = 9,
+        .data = (void *)"Hello",
+    };
+    EXPECT_TRUE(itree_insert(tree, &segment) == 1);
+    EXPECT_TRUE(itree_size(tree) == 1);
+
+    // insert
+    segment = {
+        .low = 15,
+        .high = 19,
+        .data = (void *)"World",
+    };
+    EXPECT_TRUE(itree_insert(tree, &segment) == 1);
+    EXPECT_TRUE(itree_size(tree) == 2);
+
+    // delete
+    query = {
+        .low = 1,
+        .high = 20,
+    };
+    EXPECT_TRUE(itree_remove(tree, &query) == 1);
+    EXPECT_TRUE(itree_size(tree) == 1);
+
+    // delete
+    query = {
+        .low = 1,
+        .high = 20,
+    };
+    EXPECT_TRUE(itree_remove(tree, &query) == 1);
+    EXPECT_TRUE(itree_size(tree) == 0);
+
+    itree_delete(tree);
+}
+#endif
+
+#if 1
+TEST(INTERVAL_TREE, REPEAT1)
+{
+    itree_t *tree;
+    interval_t segment;
+    interval_t query;
+
+    // new
+    tree = itree_new(my_dup, my_rel);
+    EXPECT_TRUE(tree != nullptr);
+    EXPECT_TRUE(itree_size(tree) == 0);
+
+    // insert
+    segment = {
+        .low = 5,
+        .high = 9,
+        .data = (void *)"Hello",
+    };
+    EXPECT_TRUE(itree_insert(tree, &segment) == 1);
+    EXPECT_TRUE(itree_size(tree) == 1);
+
+    // insert
+    segment = {
+        .low = 5,
+        .high = 9,
+        .data = (void *)"World",
+    };
+    EXPECT_TRUE(itree_insert(tree, &segment) == 1);
+    EXPECT_TRUE(itree_size(tree) == 2);
+
+    // remove
+    query = {
+        .low = 5,
+        .high = 9,
+    };
+    EXPECT_TRUE(itree_remove(tree, &query) == 1);
+    EXPECT_TRUE(itree_size(tree) == 1);
+    EXPECT_TRUE(itree_remove(tree, &query) == 1);
+    EXPECT_TRUE(itree_size(tree) == 0);
+
+    itree_delete(tree);
+}
+#endif
+
+#if 1 // repeat, return the fist one
+TEST(INTERVAL_TREE, REPEAT2)
+{
+    itree_t *tree;
+    ilist_t *list;
+    ilisttrav_t *trav;
+    interval_t *result;
+    interval_t query;
+    interval_t segment;
+
+    // new
+    tree = itree_new(my_dup, my_rel);
+    EXPECT_TRUE(tree != nullptr);
+    EXPECT_TRUE(itree_size(tree) == 0);
+
+    // insert
+    segment = {
+        .low = 5,
+        .high = 9,
+        .data = (void *)"Hello",
+    };
+    EXPECT_TRUE(itree_insert(tree, &segment) == 1);
+    EXPECT_TRUE(itree_size(tree) == 1);
+
+    // insert
+    segment = {
+        .low = 5,
+        .high = 9,
+        .data = (void *)"World",
+    };
+    EXPECT_TRUE(itree_insert(tree, &segment) == 1);
+    EXPECT_TRUE(itree_size(tree) == 2);
+
+    // find
+    query = {
+        .low = 5,
+        .high = 9,
+    };
+    result = itree_find(tree, &query);
+    EXPECT_TRUE(result != nullptr);
+    EXPECT_TRUE(result->low == 5);
+    EXPECT_TRUE(result->high == 9);
+    EXPECT_STREQ((const char *)result->data, "Hello");
+
+    // find all, free the repeat
+    query = {
+        .low = 5,
+        .high = 9,
+    };
+    list = itree_findall(tree, &query);
+    EXPECT_TRUE(list != nullptr);
+    EXPECT_TRUE(ilist_size(list) == 2);
+    trav = ilisttrav_new(list);
+    EXPECT_TRUE(trav != nullptr);
+
+    result = (interval_t *)ilisttrav_first(trav);
+    EXPECT_TRUE(result != nullptr);
+    EXPECT_TRUE(result->low == 5);
+    EXPECT_TRUE(result->high == 9);
+    EXPECT_STREQ((const char *)result->data, "Hello");
+
+    result = (interval_t *)ilisttrav_next(trav);
+    EXPECT_TRUE(result != nullptr);
+    EXPECT_TRUE(result->low == 5);
+    EXPECT_TRUE(result->high == 9);
+    EXPECT_STREQ((const char *)result->data, "World");
+
+    ilisttrav_delete(trav);
+    ilist_delete(list);
+
+    itree_delete(tree);
+}
+#endif
+
+int main(int argc, char **argv)
+{
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}