piece-table: Don't allocate in piece_table_to_string

`piece_table_to_string` now receives a buffer and we also provide a
function that returns the length of the piece table.

TODO: the `piece_table_to_string` adds null termination, that makes the
buffer needed `piece_table_length(pt) + 1`. This we should document or
do more obvious.

4 files changed, 38 insertions, 18 deletions

diff --git a/src/piece-table.c b/src/piece-table.c
index a8ddd1e..b29f3be 100644
--- a/src/piece-table.c
+++ b/src/piece-table.c
@@ -415,15 +415,19 @@ piece_table_index (piece_table *pt, size_t pos)
                            pt->cached->start + pos - pt->cached_offset);
 }
 
-char *
-piece_table_to_string (piece_table *pt)
+void
+piece_table_to_string (piece_table *pt, char *buf)
 {
   size_t i;
-  char *ret = malloc (sizeof (*ret) * pt->length + 1);
   for (i = 0; i < pt->length; i++)
     {
-      ret[i] = piece_table_index(pt, i);
+      buf[i] = piece_table_index (pt, i);
     }
-  ret[i] = '\0';
-  return ret;
+  buf[i] = '\0';
+}
+
+size_t
+piece_table_length (piece_table *pt)
+{
+  return pt->length;
 }
diff --git a/src/piece-table.h b/src/piece-table.h
index c9d6601..e90d2fa 100644
--- a/src/piece-table.h
+++ b/src/piece-table.h
@@ -29,6 +29,7 @@ char piece_table_index (piece_table *pt, size_t pos);
 void piece_table_insert (piece_table *pt, size_t pos, char *in, size_t len);
 void piece_table_delete (piece_table *pt, size_t pos, size_t len);
 
-char *piece_table_to_string (piece_table *pt);
+void piece_table_to_string (piece_table *pt, char *buf);
+size_t piece_table_length (piece_table *pt);
 
 #endif
diff --git a/tests/piece-table-delete.c b/tests/piece-table-delete.c
index c883b34..dc54ccc 100644
--- a/tests/piece-table-delete.c
+++ b/tests/piece-table-delete.c
@@ -6,27 +6,33 @@ int
 main()
 {
   piece_table *pt = piece_table_create("0123456789");
+  char tmp[100];
+
   piece_table_delete(pt, 0, 10);
-  if (strcmp(piece_table_to_string(pt), ""))
+  piece_table_to_string(pt, tmp);
+  if (strcmp(tmp, ""))
     return 1;
   piece_table_destroy(pt);
 
   pt = piece_table_create("0123456789");
   piece_table_delete(pt, 0, 1);
-  if (strcmp(piece_table_to_string(pt), "123456789"))
+  piece_table_to_string(pt, tmp);
+  if (strcmp(tmp, "123456789"))
     return 2;
   piece_table_destroy(pt);
 
   pt = piece_table_create("0123456789");
   piece_table_delete(pt, 9, 1);
-  if (strcmp(piece_table_to_string(pt), "012345678"))
+  piece_table_to_string(pt, tmp);
+  if (strcmp(tmp, "012345678"))
     return 3;
   piece_table_destroy(pt);
 
   pt = piece_table_create("0123456789");
   piece_table_delete(pt, 7, 1);
   piece_table_delete(pt, 0, 1);
-  if (strcmp(piece_table_to_string(pt), "12345689"))
+  piece_table_to_string(pt, tmp);
+  if (strcmp(tmp, "12345689"))
     return 4;
   piece_table_destroy(pt);
 
diff --git a/tests/piece-table-insert.c b/tests/piece-table-insert.c
index 90a97a2..bcf6dc5 100644
--- a/tests/piece-table-insert.c
+++ b/tests/piece-table-insert.c
@@ -1,19 +1,28 @@
 #include <string.h>
+#include <stdlib.h>
 #include "../src/piece-table.h"
 
 int
 main()
 {
-  piece_table *pt = piece_table_create("1234567890");
+  piece_table *pt = piece_table_create("0123456789");
+  char tmp[100];
+
   piece_table_insert(pt, 10, "abcdefgh", 8);
-  piece_table_insert(pt, 18, "abcdefgh", 8);
-  if (strcmp(piece_table_to_string(pt), "1234567890abcdefghabcdefgh"))
+  piece_table_to_string(pt, tmp);
+  if (strcmp(tmp, "0123456789abcdefgh"))
     return 1;
-  /* TODO: must have two pieces if optimized properly
-     1234567890
-     abcdefghabcdefgh
 
-     TODO: check other things too */
+  piece_table_insert(pt, 18, "abcdefgh", 8);
+  piece_table_to_string(pt, tmp);
+  if (strcmp(tmp, "0123456789abcdefghabcdefgh"))
+    return 2;
+
+  piece_table_insert(pt, 4, "abcdefgh", 8);
+  piece_table_to_string(pt, tmp);
+  if (strcmp(tmp, "0123abcdefgh456789abcdefghabcdefgh"))
+    return 3;
+
   piece_table_destroy(pt);
   return 0;
 }