WIP: Start work on pqueue-based evaluator

Need to fix ordering of entries with same priority.

1 files changed, 193 insertions, 0 deletions

diff --git a/vendor/libpqueue/pqueue.h b/vendor/libpqueue/pqueue.h
new file mode 100644
index 00000000..dadc43b8
--- /dev/null
+++ b/vendor/libpqueue/pqueue.h
@@ -0,0 +1,193 @@
+/*
+ * Copyright (c) 2014, Volkan Yazıcı <volkan.yazici@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+/**
+ * @file  pqueue.h
+ * @brief Priority Queue function declarations
+ *
+ * @{
+ */
+
+
+#ifndef PQUEUE_H
+#define PQUEUE_H
+
+/** priority data type */
+typedef unsigned long long pqueue_pri_t;
+
+/** callback functions to get/set/compare the priority of an element */
+typedef pqueue_pri_t (*pqueue_get_pri_f)(void *a);
+typedef void (*pqueue_set_pri_f)(void *a, pqueue_pri_t pri);
+typedef int (*pqueue_cmp_pri_f)(pqueue_pri_t next, pqueue_pri_t curr);
+
+
+/** callback functions to get/set the position of an element */
+typedef size_t (*pqueue_get_pos_f)(void *a);
+typedef void (*pqueue_set_pos_f)(void *a, size_t pos);
+
+
+/** debug callback function to print a entry */
+typedef void (*pqueue_print_entry_f)(FILE *out, void *a);
+
+
+/** the priority queue handle */
+typedef struct pqueue_t
+{
+    size_t size;                /**< number of elements in this queue */
+    size_t avail;               /**< slots available in this queue */
+    size_t step;                /**< growth stepping setting */
+    pqueue_cmp_pri_f cmppri;    /**< callback to compare nodes */
+    pqueue_get_pri_f getpri;    /**< callback to get priority of a node */
+    pqueue_set_pri_f setpri;    /**< callback to set priority of a node */
+    pqueue_get_pos_f getpos;    /**< callback to get position of a node */
+    pqueue_set_pos_f setpos;    /**< callback to set position of a node */
+    void **d;                   /**< The actualy queue in binary heap form */
+} pqueue_t;
+
+
+/**
+ * initialize the queue
+ *
+ * @param n the initial estimate of the number of queue items for which memory
+ *     should be preallocated
+ * @param cmppri The callback function to run to compare two elements
+ *     This callback should return 0 for 'lower' and non-zero
+ *     for 'higher', or vice versa if reverse priority is desired
+ * @param setpri the callback function to run to assign a score to an element
+ * @param getpri the callback function to run to set a score to an element
+ * @param getpos the callback function to get the current element's position
+ * @param setpos the callback function to set the current element's position
+ *
+ * @return the handle or NULL for insufficent memory
+ */
+pqueue_t *
+pqueue_init(size_t n,
+            pqueue_cmp_pri_f cmppri,
+            pqueue_get_pri_f getpri,
+            pqueue_set_pri_f setpri,
+            pqueue_get_pos_f getpos,
+            pqueue_set_pos_f setpos);
+
+
+/**
+ * free all memory used by the queue
+ * @param q the queue
+ */
+void pqueue_free(pqueue_t *q);
+
+
+/**
+ * return the size of the queue.
+ * @param q the queue
+ */
+size_t pqueue_size(pqueue_t *q);
+
+
+/**
+ * insert an item into the queue.
+ * @param q the queue
+ * @param d the item
+ * @return 0 on success
+ */
+int pqueue_insert(pqueue_t *q, void *d);
+
+
+/**
+ * move an existing entry to a different priority
+ * @param q the queue
+ * @param new_pri the new priority
+ * @param d the entry
+ */
+void
+pqueue_change_priority(pqueue_t *q,
+                       pqueue_pri_t new_pri,
+                       void *d);
+
+
+/**
+ * pop the highest-ranking item from the queue.
+ * @param q the queue
+ * @return NULL on error, otherwise the entry
+ */
+void *pqueue_pop(pqueue_t *q);
+
+
+/**
+ * remove an item from the queue.
+ * @param q the queue
+ * @param d the entry
+ * @return 0 on success
+ */
+int pqueue_remove(pqueue_t *q, void *d);
+
+
+/**
+ * access highest-ranking item without removing it.
+ * @param q the queue
+ * @return NULL on error, otherwise the entry
+ */
+void *pqueue_peek(pqueue_t *q);
+
+
+/**
+ * print the queue
+ * @internal
+ * DEBUG function only
+ * @param q the queue
+ * @param out the output handle
+ * @param the callback function to print the entry
+ */
+void
+pqueue_print(pqueue_t *q, 
+             FILE *out,
+             pqueue_print_entry_f print);
+
+
+/**
+ * dump the queue and it's internal structure
+ * @internal
+ * debug function only
+ * @param q the queue
+ * @param out the output handle
+ * @param the callback function to print the entry
+ */
+void
+pqueue_dump(pqueue_t *q, 
+             FILE *out,
+             pqueue_print_entry_f print);
+
+
+/**
+ * checks that the pq is in the right order, etc
+ * @internal
+ * debug function only
+ * @param q the queue
+ */
+int pqueue_is_valid(pqueue_t *q);
+
+
+#endif /* PQUEUE_H */
+/** @} */