[feat] support ttl compact.

deps/Makefile

@@ -39,6 +39,7 @@ distclean:
 	-(cd jemalloc && [ -f Makefile ] && $(MAKE) distclean) > /dev/null || true
 	-(cd hdr_histogram && $(MAKE) clean) > /dev/null || true
 	-(cd xredis-gtid && [ -f Makefile ] && $(MAKE) clean) > /dev/null || true
+	-(cd tdigest && $(MAKE) clean) > /dev/null || true
 	-(rm -f .make-*)
 
 .PHONY: distclean
@@ -65,6 +66,14 @@ hdr_histogram: .make-prerequisites
 
 .PHONY: hdr_histogram
 
+TDIGEST_CFLAGS= -I./include -I../../src
+
+tdigest: .make-prerequisites
+	@printf '%b %b\n' $(MAKECOLOR)MAKE$(ENDCOLOR) $(BINCOLOR)$@$(ENDCOLOR)
+	cd tdigest && $(MAKE) CFLAGS="$(TDIGEST_CFLAGS)"
+
+.PHONY: tdigest
+
 ifeq ($(uname_S),SunOS)
 	# Make isinf() available
 	LUA_CFLAGS= -D__C99FEATURES__=1

deps/tdigest/Makefile

@@ -0,0 +1,18 @@
+STD=
+WARN= -Wall
+OPT= -Os
+
+R_CFLAGS= $(STD) $(WARN) $(OPT) $(DEBUG) $(CFLAGS)
+R_LDFLAGS= $(LDFLAGS)
+DEBUG= -g
+
+R_CC=$(CC) $(R_CFLAGS)
+R_LD=$(CC) $(R_LDFLAGS)
+
+tdigest.o: tdigest.h tdigest.c
+
+.c.o:
+	$(R_CC) -c  $< 
+
+clean:
+	rm -f *.o