thresholds: use dedicated storage

Instead of a Host and IPPair table thresholding layer, use a dedicated
THash to store both. This allows hashing on host+sid+tracker or
ippair+sid+tracker, to create more unique hash keys.

This allows for fewer hash collisions.

The per rule tracking also uses this, so that the single big lock is no
longer a single point of contention.

Reimplement storage for flow thresholds to reuse as much logic as
possible from the host/ippair/rule thresholds.

Ticket: OISF#426.

src/detect-detection-filter.c

@@ -378,7 +378,7 @@ static int DetectDetectionFilterTestSig1(void)
     ThreadVars th_v;
     DetectEngineThreadCtx *det_ctx;
 
-    HostInitConfig(HOST_QUIET);
+    ThresholdInit();
 
     memset(&th_v, 0, sizeof(th_v));
 
@@ -418,7 +418,7 @@ static int DetectDetectionFilterTestSig1(void)
     DetectEngineCtxFree(de_ctx);
 
     UTHFreePackets(&p, 1);
-    HostShutdown();
+    ThresholdDestroy();
 
     PASS;
 }
@@ -435,7 +435,7 @@ static int DetectDetectionFilterTestSig2(void)
     ThreadVars th_v;
     DetectEngineThreadCtx *det_ctx;
 
-    HostInitConfig(HOST_QUIET);
+    ThresholdInit();
 
     memset(&th_v, 0, sizeof(th_v));
 
@@ -480,7 +480,7 @@ static int DetectDetectionFilterTestSig2(void)
     DetectEngineCtxFree(de_ctx);
 
     UTHFreePackets(&p, 1);
-    HostShutdown();
+    ThresholdDestroy();
 
     PASS;
 }
@@ -493,7 +493,7 @@ static int DetectDetectionFilterTestSig3(void)
     ThreadVars th_v;
     DetectEngineThreadCtx *det_ctx;
 
-    HostInitConfig(HOST_QUIET);
+    ThresholdInit();
 
     memset(&th_v, 0, sizeof(th_v));
 
@@ -556,7 +556,7 @@ static int DetectDetectionFilterTestSig3(void)
     DetectEngineCtxFree(de_ctx);
 
     UTHFreePackets(&p, 1);
-    HostShutdown();
+    ThresholdDestroy();
 
     PASS;
 }

src/detect-engine-build.c

@@ -2219,8 +2219,6 @@ int SigGroupBuild(DetectEngineCtx *de_ctx)
     SCProfilingRuleInitCounters(de_ctx);
 #endif
 
-    ThresholdHashAllocate(de_ctx);
-
     if (!DetectEngineMultiTenantEnabled()) {
         VarNameStoreActivate();
     }