mpv: fire only one report when simple-exhaustible

src/nfa/mpv.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Intel Corporation
+ * Copyright (c) 2015-2016, Intel Corporation
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -124,7 +124,7 @@ char processReports(const struct mpv *m, u8 *reporters,
                 DEBUG_PRINTF("report %u at %llu\n", curr->report,
                               report_offset);
 
-                if (curr->unbounded) {
+                if (curr->unbounded && !curr->simple_exhaust) {
                     assert(rl_count < m->puffette_count);
                     *rl = curr->report;
                     ++rl;
@@ -176,6 +176,8 @@ char processReportsForRange(const struct mpv *m, u8 *reporters,
         return MO_CONTINUE_MATCHING;
     }
 
+    DEBUG_PRINTF("length=%zu, rl_count=%u\n", length, rl_count);
+
     for (size_t i = 2; i <= length; i++) {
         for (u32 j = 0; j < rl_count; j++) {
             if (cb(first_offset + i, rl[j], ctxt) == MO_HALT_MATCHING) {

src/nfa/mpv_dump.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Intel Corporation
+ * Copyright (c) 2015-2016, Intel Corporation
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -108,6 +108,9 @@ void dumpKilo(FILE *f, const mpv *m, const mpv_kilopuff *k) {
         fprintf(f, "    Puffette %u\n", i);
         fprintf(f, "        repeats:   %u%s\n", p[i].repeats,
                 p[i].unbounded ? "," : "");
+        if (p[i].simple_exhaust) {
+            fprintf(f, "        simple exhaustible\n");
+        }
         fprintf(f, "        report id: %u\n", p[i].report);
     }
 

src/nfa/mpv_internal.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Intel Corporation
+ * Copyright (c) 2015-2016, Intel Corporation
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -40,6 +40,15 @@
 struct mpv_puffette {
     u32 repeats;
     char unbounded;
+
+    /**
+     * \brief Report is simple-exhaustible.
+     *
+     * If this is true, we do best-effort suppression of runs of reports, only
+     * delivering the first one.
+     */
+    char simple_exhaust;
+
     ReportID report;
 };
 

src/nfa/mpvcompile.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Intel Corporation
+ * Copyright (c) 2015-2016, Intel Corporation
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -53,10 +53,8 @@ namespace ue2 {
 namespace {
 struct pcomp {
     bool operator()(const raw_puff &a, const raw_puff &b) const {
-        ORDER_CHECK(repeats);
-        ORDER_CHECK(unbounded);
-        ORDER_CHECK(report);
-        return false;
+        return tie(a.repeats, a.unbounded, a.simple_exhaust, a.report) <
+               tie(b.repeats, b.unbounded, b.simple_exhaust, b.report);
     }
 };
 
@@ -89,6 +87,7 @@ void writePuffette(mpv_puffette *out, const raw_puff &rp) {
                  rp.report, out);
     out->repeats = rp.repeats;
     out->unbounded = rp.unbounded;
+    out->simple_exhaust = rp.simple_exhaust;
     out->report = rp.report;
 }
 

src/nfa/mpvcompile.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Intel Corporation
+ * Copyright (c) 2015-2016, Intel Corporation
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -42,12 +42,15 @@ namespace ue2 {
 
 struct raw_puff {
     raw_puff(u32 repeats_in, bool unbounded_in, ReportID report_in,
-             const CharReach &reach_in, bool auto_restart_in = false)
+             const CharReach &reach_in, bool auto_restart_in = false,
+             bool simple_exhaust_in = false)
         : repeats(repeats_in), unbounded(unbounded_in),
-          auto_restart(auto_restart_in), report(report_in), reach(reach_in) {}
+          auto_restart(auto_restart_in), simple_exhaust(simple_exhaust_in),
+          report(report_in), reach(reach_in) {}
     u32 repeats; /**< report match after this many matching bytes */
     bool unbounded; /**< keep producing matches after repeats are reached */
     bool auto_restart; /**< for /[^X]{n}/ type patterns */
+    bool simple_exhaust; /* first report will exhaust us */
     ReportID report;
     CharReach reach; /**< = ~escapes */
 };

src/nfagraph/ng_puff.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Intel Corporation
+ * Copyright (c) 2015-2016, Intel Corporation
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -270,12 +270,16 @@ void constructPuff(NGHolder &g, const NFAVertex a, const NFAVertex puffv,
     DEBUG_PRINTF("constructing Puff for report %u\n", report);
     DEBUG_PRINTF("a = %u\n", g[a].index);
 
+    const Report &puff_report = rm.getReport(report);
+    const bool simple_exhaust = isSimpleExhaustible(puff_report);
+
     const bool pureAnchored = a == g.start && singleStart(g);
     if (!pureAnchored) {
         if (a == g.startDs || a == g.start) {
             DEBUG_PRINTF("add outfix ar(false)\n");
 
-            raw_puff rp(width, unbounded, report, cr, auto_restart);
+            raw_puff rp(width, unbounded, report, cr, auto_restart,
+                        simple_exhaust);
             rose.addOutfix(rp);
             return;
         }
@@ -300,7 +304,7 @@ void constructPuff(NGHolder &g, const NFAVertex a, const NFAVertex puffv,
     } else {
         DEBUG_PRINTF("add outfix ar(%d)\n", (int)auto_restart);
         assert(!auto_restart || unbounded);
-        raw_puff rp(width, unbounded, report, cr, auto_restart);
+        raw_puff rp(width, unbounded, report, cr, auto_restart, simple_exhaust);
         rose.addOutfix(rp);
     }
 }