1 files changed, 69 insertions, 0 deletions
diff --git a/userland/libc/tb/sb.c b/userland/libc/tb/sb.c
new file mode 100644
index 0000000..0d0ec52
--- /dev/null
+++ b/userland/libc/tb/sb.c
@@ -0,0 +1,69 @@
+#include <tb/sb.h>
+#include <math.h>
+#include <stdlib.h>
+#include <string.h>
+
+void sb_init(struct sb *ctx) {
+  ctx->string = malloc(512);
+  ctx->length = 0;
+  ctx->capacity = 512;
+}
+
+void sb_free(struct sb *ctx) {
+  ctx->length = 0;
+  ctx->capacity = 0;
+  free(ctx->string);
+  ctx->string = NULL;
+}
+
+void sb_reset(struct sb *ctx) {
+  ctx->length = 0;
+}
+
+int sb_isempty(const struct sb *ctx) {
+  return (0 == ctx->length);
+}
+
+void sb_append_char(struct sb *ctx, char c) {
+  if (1 > ctx->capacity - ctx->length) {
+    ctx->capacity += 32;
+    ctx->string = realloc(ctx->string, ctx->capacity);
+  }
+  memcpy(ctx->string + ctx->length, &c, 1);
+  ctx->length++;
+}
+
+int sb_delete_right(struct sb *ctx, int n) {
+  n = min(n, ctx->length);
+  ctx->length -= n;
+  return n;
+}
+
+void sb_append(struct sb *ctx, const char *s) {
+  size_t l = strlen(s);
+  if (l > ctx->capacity - ctx->length) {
+    ctx->capacity += l;
+    ctx->string = realloc(ctx->string, ctx->capacity);
+  }
+  memcpy(ctx->string + ctx->length, s, l);
+  ctx->length += l;
+}
+
+void sb_prepend_sv(struct sb *ctx, struct sv sv) {
+  if (sv.length > ctx->capacity - ctx->length) {
+    ctx->capacity += sv.length;
+    ctx->string = realloc(ctx->string, ctx->capacity);
+  }
+  memmove(ctx->string + sv.length, ctx->string, ctx->length);
+  memcpy(ctx->string, sv.s, sv.length);
+  ctx->length += sv.length;
+}
+
+void sb_append_sv(struct sb *ctx, struct sv sv) {
+  if (sv.length > ctx->capacity - ctx->length) {
+    ctx->capacity += sv.length;
+    ctx->string = realloc(ctx->string, ctx->capacity);
+  }
+  memcpy(ctx->string + ctx->length, sv.s, sv.length);
+  ctx->length += sv.length;
+}