sbstring implmentation and first use.

src/reports.c

@@ -2035,6 +2035,7 @@ void report_battle_start(battle * b)
 {
     bfaction *bf;
     char zText[32 * MAXSIDES];
+    sbstring sbs;
 
     for (bf = b->factions; bf; bf = bf->next) {
         message *m;
@@ -2042,18 +2043,17 @@ void report_battle_start(battle * b)
         const char *lastf = NULL;
         bool first = false;
         side *s;
-        char *bufp = zText;
-        size_t size = sizeof(zText) - 1;
 
+        sbs_init(&sbs, zText, sizeof(zText));
         for (s = b->sides; s != b->sides + b->nsides; ++s) {
             fighter *df;
             for (df = s->fighters; df; df = df->next) {
                 if (is_attacker(df)) {
                     if (first) {
-                        bufp += str_strlcpy(bufp, ", ", size);
+                        sbs_strcpy(&sbs, ", ");
                     }
                     if (lastf) {
-                        bufp += str_strlcpy(bufp, lastf, size);
+                        sbs_strcpy(&sbs, lastf);
                         first = true;
                     }
                     if (seematrix(f, s))
@@ -2065,12 +2065,12 @@ void report_battle_start(battle * b)
             }
         }
         if (first) {
-            bufp = STRLCPY(bufp, " ", size);
-            bufp = STRLCPY(bufp, LOC(f->locale, "and"), size);
-            bufp = STRLCPY(bufp, " ", size);
+            sbs_strcpy(&sbs, " ");
+            sbs_strcpy(&sbs, LOC(f->locale, "and"));
+            sbs_strcpy(&sbs, " ");
         }
         if (lastf) {
-            bufp = STRLCPY(bufp, lastf, size);
+            sbs_strcpy(&sbs, lastf);
         }
 
         m = msg_message("start_battle", "factions", zText);

src/util/strings.c

@@ -238,3 +238,28 @@ char *str_strdup(const char *s) {
     return strdup(s);
 #endif
 }
+
+void sbs_init(struct sbstring *sbs, char *buffer, size_t size)
+{
+    assert(sbs);
+    assert(size>0);
+    sbs->begin = buffer;
+    sbs->size = size;
+    sbs->end = buffer;
+    buffer[0] = '\0';
+}
+
+void sbs_strcat(struct sbstring *sbs, const char *str)
+{
+    size_t len;
+    assert(sbs);
+    len = sbs->size - (sbs->end - sbs->begin);
+    len = str_strlcpy(sbs->end, str, len);
+    sbs->end += len;
+}
+
+void sbs_strcpy(struct sbstring *sbs, const char *str)
+{
+    size_t len = str_strlcpy(sbs->begin, str, sbs->size);
+    sbs->end += len;
+}

src/util/strings.h

@@ -37,6 +37,17 @@ extern "C" {
     unsigned int jenkins_hash(unsigned int a);
     unsigned int wang_hash(unsigned int a);
 
+    /* static buffered string */
+    typedef struct sbstring {
+        size_t size;
+        char *begin;
+        char *end;
+    } sbstring;
+
+    void sbs_init(struct sbstring *sbs, char *buffer, size_t size);
+    void sbs_strcat(struct sbstring *sbs, const char *str);
+    void sbs_strcpy(struct sbstring *sbs, const char *str);
+
     /* benchmark for units:
      * JENKINS_HASH: 5.25 misses/hit (with good cache behavior)
      * WANG_HASH:    5.33 misses/hit (with good cache behavior)

src/util/strings.test.c

@@ -91,6 +91,25 @@ static void test_str_strlcpy(CuTest * tc)
     errno = 0;
 }
 
+static void test_sbstring(CuTest * tc)
+{
+    char buffer[16];
+    sbstring sbs;
+    sbs_init(&sbs, buffer, sizeof(buffer));
+    CuAssertStrEquals(tc, "", sbs.begin);
+    sbs_strcpy(&sbs, "Hodor");
+    CuAssertStrEquals(tc, "Hodor", sbs.begin);
+    sbs_strcat(&sbs, "Hodor");
+    CuAssertStrEquals(tc, "HodorHodor", sbs.begin);
+    sbs_strcpy(&sbs, "Hodor");
+    CuAssertStrEquals(tc, "Hodor", sbs.begin);
+    sbs_strcpy(&sbs, "12345678901234567890");
+    CuAssertStrEquals(tc, "123456789012345", sbs.begin);
+    sbs_strcat(&sbs, "12345678901234567890");
+    CuAssertStrEquals(tc, "123456789012345", sbs.begin);
+    CuAssertStrEquals(tc, buffer, sbs.begin);
+}
+
 CuSuite *get_strings_suite(void)
 {
     CuSuite *suite = CuSuiteNew();
@@ -100,5 +119,6 @@ CuSuite *get_strings_suite(void)
     SUITE_ADD_TEST(suite, test_str_slprintf);
     SUITE_ADD_TEST(suite, test_str_strlcat);
     SUITE_ADD_TEST(suite, test_str_strlcpy);
+    SUITE_ADD_TEST(suite, test_sbstring);
     return suite;
 }