txt_save()

1 files changed, 52 insertions, 12 deletions

diff --git a/txt.c b/txt.c
index daa02e5..9f29f84 100644
--- a/txt.c
+++ b/txt.c
@@ -10,10 +10,16 @@
 #include "dynarr.h"
 #include "txt.h"
 
+void txt_replace_piece(Txt *b, u32 pi, TxtBufIdx buf, u32 ofs, u32 n) { 
+	b->ptbl.v[pi] = (TxtPiece) { buf, ofs, n };
+}
+
 void txt_insert_piece(Txt *b, u32 pi, TxtBufIdx buf, u32 ofs, u32 n) { 
 	DA_FIT(&b->ptbl, b->ptbl.n + 1);
-	MOVE(&b->ptbl.v[pi+1], &b->ptbl.v[pi], b->ptbl.n - pi);
-	b->ptbl.v[pi] = (TxtPiece) { buf, ofs, n };
+	if (pi < b->ptbl.n) {
+		MOVE(&b->ptbl.v[pi+1], &b->ptbl.v[pi], b->ptbl.n - pi);
+	}
+	txt_replace_piece(b, pi, buf, ofs, n);
 	b->ptbl.n++;
 }
 
@@ -43,13 +49,18 @@ TxtLoc txt_at(Txt *b, u32 cur) {
 	return (TxtLoc) { b->ptbl.n - 1, b->ptbl.v[b->ptbl.n - 1].n };
 }
 
-void txt_buf_append(Txt *b, TxtBufIdx bi, const char *s, u32 n) {
+static void txt_buf_fit(Txt *b, TxtBufIdx bi, u32 sz) {
 	TxtBuf *buf = &b->buf[bi];
-	if (buf->n + n > buf->c) {
-		buf->c = stdc_bit_ceil(buf->n + n);
+	if (sz > buf->c) {
+		buf->c = stdc_bit_ceil(sz);
 		buf->s = realloc(buf->s, buf->c);
 		if (!buf->s) FAIL_WITH_MSG("realloc failure");
 	}
+}
+
+static void txt_buf_append(Txt *b, TxtBufIdx bi, const char *s, u32 n) {
+	TxtBuf *buf = &b->buf[bi];
+	txt_buf_fit(b, bi, buf->n + n);
 	memcpy(&buf->s[buf->n], s, n);
 	buf->n += n;
 }
@@ -68,8 +79,11 @@ u32 txt_add_piece(Txt *b, TxtLoc l) {
 		}
 	} else {
 insert:
-		if (b->ptbl.v[l.p].n == 0) txt_remove_piece(b, l.p);
-		txt_insert_piece(b, l.p, TXT_ADD, b->buf[TXT_ADD].n, 0);
+		if (l.p < b->ptbl.n && b->ptbl.v[l.p].n == 0) {
+			txt_replace_piece(b, l.p, TXT_ADD, b->buf[TXT_ADD].n, 0);
+		} else {
+			txt_insert_piece(b, l.p, TXT_ADD, b->buf[TXT_ADD].n, 0);
+		}
 	}
 	return l.p;
 }
@@ -130,7 +144,7 @@ u32 txt_delete(Txt *b, u32 cur, u32 n) {
 	return cur;
 }
 
-int txt_open(Txt *b, const char *path) {
+int txt_load(Txt *b, const char *path) {
 	struct stat sb;
 	int fd = open(path, O_RDONLY);
 	if (fd == -1) return -1;
@@ -138,17 +152,43 @@ int txt_open(Txt *b, const char *path) {
 		close(fd);
 		return -1;
 	}
+	if (!sb.st_size) {
+		txt_buf_fit(b, TXT_SRC, 8192);
+		goto done;
+	}
 	void *m = mmap(0, sb.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 	if (m == MAP_FAILED) {
 		close(fd);
 		return -1;
 	}
-	memset(b, 0, sizeof(TxtBuf));
-	b->buf[TXT_SRC].s = m;
+	txt_buf_fit(b, TXT_SRC, sb.st_size);
+	memcpy(b->buf[TXT_SRC].s, m, sb.st_size);
+	munmap(m, sb.st_size);
 	b->buf[TXT_SRC].n = sb.st_size;
-	b->buf[TXT_SRC].c = sb.st_size;
-	b->len = sb.st_size;
 	close(fd);
+done:
+	b->ptbl.n = 0;
+	b->buf[TXT_ADD].n = 0;
+	b->len = b->buf[TXT_SRC].n;
 	txt_insert_piece(b, 0, TXT_SRC, 0, b->len);
 	return 0;
 }
+
+int txt_save(Txt *t, const char *path) {
+	FILE *f = fopen(path, "w");
+	if (!f) return -1;
+	for (u32 i = 0; i < t->ptbl.n; i++) {
+		TxtPiece *p = &t->ptbl.v[i];
+		TxtBuf *b = &t->buf[p->buf];
+		fwrite(b->s + p->ofs, 1, p->n, f);
+	}
+	fclose(f);
+	return ferror(f) ? -1 : 0;
+}
+
+void txt_free(Txt *t) {
+	for (u32 i = 0; i < COUNTOF(t->buf); i++) {
+		free(t->buf[i].s);
+	}
+	free(t->ptbl.v);
+}