string stuff

5 files changed, 78 insertions, 8 deletions

diff --git a/src/smrt_arena.c b/src/smrt_arena.c
index 683afcd..0fb8ab7 100644
--- a/src/smrt_arena.c
+++ b/src/smrt_arena.c
@@ -127,6 +127,10 @@ void smrt_arena_clear(smrt_arena_t *arena, b32 zero_out) {
     smrt_arena__shrink_commit(arena);
 }
 
+void smrt_arena_mark(smrt_arena_t *arena) {
+    arena->mark_pos = arena->pos;
+}
+
 void smrt_arena_destroy(smrt_arena_t *arena) {
     plat_mem_release(arena, arena->reserve_size);
 }
diff --git a/src/smrt_arena.h b/src/smrt_arena.h
index 4e6f592..375929d 100644
--- a/src/smrt_arena.h
+++ b/src/smrt_arena.h
@@ -23,6 +23,7 @@ smrt_arena_t     *smrt_arena_create(u64 reserve_size, u64 commit_size, b32 auto_
         void      smrt_arena_pop_to(smrt_arena_t *arena, u64 location);
          b32 smrt_arena_pop_to_mark(smrt_arena_t *arena);
         void       smrt_arena_clear(smrt_arena_t *arena, b32 zero_out);
+        void        smrt_arena_mark(smrt_arena_t *arena);
         void     smrt_arena_destroy(smrt_arena_t *arena);
 
 #define SMRTA_ALLOC_ARRAY(arena, T, n) (T*)smrt_arena_push(arena, sizeof(T) * (n), true)
diff --git a/src/string.c b/src/string.c
index 9328911..a29af19 100644
--- a/src/string.c
+++ b/src/string.c
@@ -15,7 +15,7 @@ strng_t *strng_new(smrt_arena_t *arena, u64 size) {
     return s;
 }
 
-strng_t *strng_from(smrt_arena_t *arena, char *c) {
+strng_t *strng_from(smrt_arena_t *arena, char const *c) {
     u64 size = strlen(c);
 
     strng_t *s = strng_new(arena, size);
@@ -30,7 +30,38 @@ strng_t *strng_from(smrt_arena_t *arena, char *c) {
     return s;
 }
 
-b32 strng_set(strng_t *string, char *c) {
+strng_t *strng_dup(smrt_arena_t *arena, strng_t const *src) {
+    u64 size = src->len + sizeof(strng_t);
+
+    strng_t *string = smrt_arena_push(arena, size, true);
+
+    if (!string) {
+        return NULL;
+    }
+
+    string->alloc_size = src->len;
+
+    memcpy((u8*)string+STRNG_BASE_POS, (u8*)src+STRNG_BASE_POS, src->len);
+    string->len = src->len;
+
+    return string;
+}
+
+char *strng_str(smrt_arena_t *arena, strng_t const *string) {
+    char *s = SMRTA_ALLOC_ARRAY(arena, char, string->len+1);
+
+    if (!s) {
+        return NULL;
+    } else if (string->len == 0) {
+        return s;
+    }
+
+    memcpy(s, (u8*)string+STRNG_BASE_POS, string->len);
+
+    return s;
+}
+
+b32 strng_set(strng_t *string, char const *c) {
     u64 size = strlen(c);
 
     if (string->alloc_size < size) {
@@ -44,5 +75,6 @@ b32 strng_set(strng_t *string, char *c) {
 }
 
 void strng_clear(strng_t *string) {
+    memset((u8*)string+STRNG_BASE_POS, 0, string->len);
     string->len = 0;
 }
diff --git a/src/string.h b/src/string.h
index b8554ff..419ef96 100644
--- a/src/string.h
+++ b/src/string.h
@@ -11,8 +11,10 @@ typedef struct {
 } strng_t;
 
 strng_t  *strng_new(smrt_arena_t *arena, u64 size);
-strng_t *strng_from(smrt_arena_t *arena, char *c);
-    b32   strng_set(strng_t *string, char *c);
+strng_t *strng_from(smrt_arena_t *arena, char const *c);
+strng_t  *strng_dup(smrt_arena_t *arena, strng_t const *src);
+   char  *strng_str(smrt_arena_t *arena, strng_t const *string);
+    b32   strng_set(strng_t *string, char const *c);
    void strng_clear(strng_t *string);
 
 #define STRNG_FMT(s) (int)s->len, (char *)((u8*)s+STRNG_BASE_POS)
diff --git a/tests/string.c b/tests/string.c
index 0e78168..38109a7 100644
--- a/tests/string.c
+++ b/tests/string.c
@@ -24,8 +24,20 @@ Test(string, from_cstring) {
 
     cr_expect(s->alloc_size == 13);
     cr_expect(s->len == 13);
-    cr_expect(*((u8*)s+STRNG_BASE_POS) == 72);
-    cr_expect(*((u8*)s+STRNG_BASE_POS+s->len-1) == 46);
+    cr_expect(*((u8*)s+STRNG_BASE_POS) == 'H');
+    cr_expect(*((u8*)s+STRNG_BASE_POS+s->len-1) == '.');
+
+    smrt_arena_destroy(arena);
+}
+
+Test(string, to_cstring) {
+    smrt_arena_t *arena = smrt_arena_create(KiB(4), KiB(4), false);
+    strng_t *s = strng_from(arena, "Heavy is the head");
+
+    char *c = strng_str(arena, s);
+
+    cr_expect(strlen(c) == 17);
+    cr_expect(strcmp(c, "Heavy is the head") == 0);
 
     smrt_arena_destroy(arena);
 }
@@ -38,8 +50,26 @@ Test(string, set_string) {
 
     cr_expect(s->alloc_size == 13);
     cr_expect(s->len == 8);
-    cr_expect(*((u8*)s+STRNG_BASE_POS) == 76);
-    cr_expect(*((u8*)s+STRNG_BASE_POS+s->len-1) == 33);
+    cr_expect(*((u8*)s+STRNG_BASE_POS) == 'L');
+    cr_expect(*((u8*)s+STRNG_BASE_POS+s->len-1) == '!');
+
+    smrt_arena_destroy(arena);
+}
+
+Test(string, string_duplicate) {
+    smrt_arena_t *arena = smrt_arena_create(KiB(4), KiB(4), false);
+
+    strng_t *orig = strng_new(arena, 50);
+    strng_set(orig,  "that falls with the weight");
+
+
+    strng_t *dup = strng_dup(arena, orig);
+    printf("%.*s\n", STRNG_FMT(dup));
+
+    cr_expect(dup->alloc_size == 26);
+    cr_expect(dup->len == 26);
+    cr_expect(*((u8*)dup+STRNG_BASE_POS) == 't');
+    cr_expect(*((u8*)dup+STRNG_BASE_POS+dup->len-1) == 't');
 
     smrt_arena_destroy(arena);
 }
@@ -51,6 +81,7 @@ Test(string, format_and_copy_string) {
     char *buffer = SMRTA_ALLOC_ARRAY(arena, char, s->len+1);
 
     u64 copied = snprintf(buffer, s->len+1, "%.*s", STRNG_FMT(s));
+
     cr_expect(copied == 13);
     cr_expect(strcmp(buffer, "Hello, world.") == 0);