chore: import t-digest-c lib (#5102)

* import t-digest-c lib

---------

Signed-off-by: kostas <[email protected]>

Author: kostasrim

src/redis/CMakeLists.txt

@@ -12,7 +12,7 @@ add_library(redis_lib crc16.c crc64.c crcspeed.c debug.c  intset.c geo.c
             geohash.c geohash_helper.c t_zset.c
             listpack.c lzf_c.c lzf_d.c sds.c
             quicklist.c rax.c redis_aux.c t_stream.c 
-            util.c ziplist.c hyperloglog.c ${ZMALLOC_SRC})
+            util.c ziplist.c hyperloglog.c tdigest.c ${ZMALLOC_SRC})
 
 cxx_link(redis_lib  ${ZMALLOC_DEPS})
 

src/redis/t-digest.LICENSE.md

@@ -0,0 +1,21 @@
+# MIT License
+
+Copyright (c) 2019 Bob Rudis
+
+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.

src/redis/td_malloc.h

@@ -0,0 +1,21 @@
+/**
+ * Adaptive histogram based on something like streaming k-means crossed with Q-digest.
+ * The implementation is a direct descendent of MergingDigest
+ * https://github.com/tdunning/t-digest/
+ *
+ * Copyright (c) 2021 Redis, All rights reserved.
+ *
+ * Allocator selection.
+ *
+ * This file is used in order to change the t-digest allocator at compile time.
+ * Just define the following defines to what you want to use. Also add
+ * the include of your alternate allocator if needed (not needed in order
+ * to use the default libc allocator). */
+
+#ifndef TD_ALLOC_H
+#define TD_ALLOC_H
+#define __td_malloc malloc
+#define __td_calloc calloc
+#define __td_realloc realloc
+#define __td_free free
+#endif