sync code with last improvements from OpenBSD

2023-08-28 05:57:34 +00:00 · 2023-08-28 05:57:34 +00:00 · 88965415ff
commit 88965415ff
26235 changed files with 29195616 additions and 0 deletions
--- a/xserver/Xext/hashtable.h
+++ b/xserver/Xext/hashtable.h
@ -0,0 +1,137 @@
+#ifndef HASHTABLE_H
+#define HASHTABLE_H 1
+
+#include <dix-config.h>
+#include <X11/Xfuncproto.h>
+#include <X11/Xdefs.h>
+#include "list.h"
+
+/** @brief A hashing function.
+
+  @param[in/out] cdata  Opaque data that can be passed to HtInit that will
+                        eventually end up here
+  @param[in] ptr        The data to be hashed. The size of the data, if
+                        needed, can be configured via a record that can be
+                        passed via cdata.
+  @param[in] numBits    The number of bits this hash needs to have in the
+                        resulting hash
+
+  @return  A numBits-bit hash of the data
+*/
+typedef unsigned (*HashFunc)(void * cdata, const void * ptr, int numBits);
+
+/** @brief A comparison function for hashed keys.
+
+  @param[in/out] cdata  Opaque data that ca be passed to Htinit that will
+                        eventually end up here
+  @param[in] l          The left side data to be compared
+  @param[in] r          The right side data to be compared
+
+  @return -1 if l < r, 0 if l == r, 1 if l > r
+*/
+typedef int (*HashCompareFunc)(void * cdata, const void * l, const void * r);
+
+struct HashTableRec;
+
+typedef struct HashTableRec *HashTable;
+
+/** @brief  A configuration for HtGenericHash */
+typedef struct {
+    int             keySize;
+} HtGenericHashSetupRec, *HtGenericHashSetupPtr;
+
+/** @brief  ht_create initializes a hash table for a certain hash table
+            configuration
+
+    @param[out] ht       The hash table structure to initialize
+    @param[in] keySize   The key size in bytes
+    @param[in] dataSize  The data size in bytes
+    @param[in] hash      The hash function to use for hashing keys
+    @param[in] compare   The comparison function for hashing keys
+    @param[in] cdata     Opaque data that will be passed to hash and
+                         comparison functions
+*/
+extern _X_EXPORT HashTable ht_create(int             keySize,
+                                     int             dataSize,
+                                     HashFunc        hash,
+                                     HashCompareFunc compare,
+                                     void            *cdata);
+/** @brief  HtDestruct deinitializes the structure. It does not free the
+            memory allocated to HashTableRec
+*/
+extern _X_EXPORT void ht_destroy(HashTable ht);
+
+/** @brief  Adds a new key to the hash table. The key will be copied
+            and a pointer to the value will be returned. The data will
+            be initialized with zeroes.
+
+  @param[in/out] ht  The hash table
+  @param[key] key    The key. The contents of the key will be copied.
+
+  @return On error NULL is returned, otherwise a pointer to the data
+          associated with the newly inserted key.
+
+  @note  If dataSize is 0, a pointer to the end of the key may be returned
+         to avoid returning NULL. Obviously the data pointed cannot be
+         modified, as implied by dataSize being 0.
+*/
+extern _X_EXPORT void *ht_add(HashTable ht, const void *key);
+
+/** @brief  Removes a key from the hash table along with its
+            associated data, which will be free'd.
+*/
+extern _X_EXPORT void ht_remove(HashTable ht, const void *key);
+
+/** @brief  Finds the associated data of a key from the hash table.
+
+   @return  If the key cannot be found, the function returns NULL.
+            Otherwise it returns a pointer to the data associated
+            with the key.
+
+   @note  If dataSize == 0, this function may return NULL
+          even if the key has been inserted! If dataSize == NULL,
+          use HtMember instead to determine if a key has been
+          inserted.
+*/
+extern _X_EXPORT void *ht_find(HashTable ht, const void *key);
+
+/** @brief  A generic hash function */
+extern _X_EXPORT unsigned ht_generic_hash(void *cdata,
+                                          const void *ptr,
+                                          int numBits);
+
+/** @brief  A generic comparison function. It compares data byte-wise. */
+extern _X_EXPORT int ht_generic_compare(void *cdata,
+                                        const void *l,
+                                        const void *r);
+
+/** @brief  A debugging function that dumps the distribution of the
+            hash table: for each bucket, list the number of elements
+            contained within. */
+extern _X_EXPORT void ht_dump_distribution(HashTable ht);
+
+/** @brief  A debugging function that dumps the contents of the hash
+            table: for each bucket, list the elements contained
+            within. */
+extern _X_EXPORT void ht_dump_contents(HashTable ht,
+                                       void (*print_key)(void *opaque, void *key),
+                                       void (*print_value)(void *opaque, void *value),
+                                       void* opaque);
+
+/** @brief  A hashing function to be used for hashing resource IDs when
+            used with HashTables. It makes no use of cdata, so that can
+            be NULL. It uses HashXID underneath, and should HashXID be
+            unable to hash the value, it switches into using the generic
+            hash function. */
+extern _X_EXPORT unsigned ht_resourceid_hash(void *cdata,
+                                             const void * data,
+                                             int numBits);
+
+/** @brief  A comparison function to be used for comparing resource
+            IDs when used with HashTables. It makes no use of cdata,
+            so that can be NULL. */
+extern _X_EXPORT int ht_resourceid_compare(void *cdata,
+                                           const void *a,
+                                           const void *b);
+
+#endif // HASHTABLE_H