stdlib/strings: Added cache on Buffer.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>

diff --git a/lib/standard/string.nit b/lib/standard/string.nit
index ff18a7d..b34e043 100644 (file)
--- a/lib/standard/string.nit
+++ b/lib/standard/string.nit
@@ -991,6 +991,8 @@ abstract class Buffer
        redef type SELFVIEW: BufferCharView
        redef type SELFTYPE: Buffer
 
+       var is_dirty = true
+
        # Modifies the char contained at pos `index`
        #
        # DEPRECATED : Use self.chars.[]= instead
@@ -1026,6 +1028,7 @@ class FlatBuffer
 
        redef fun []=(index, item)
        do
+               is_dirty = true
                if index == length then
                        add(item)
                        return
@@ -1036,17 +1039,22 @@ class FlatBuffer
 
        redef fun add(c)
        do
+               is_dirty = true
                if capacity <= length then enlarge(length + 5)
                items[length] = c
                length += 1
        end
 
-       redef fun clear do length = 0
+       redef fun clear do
+               is_dirty = true
+               length = 0
+       end
 
        redef fun empty do return new FlatBuffer
 
        redef fun enlarge(cap)
        do
+               is_dirty = true
                var c = capacity
                if cap <= c then return
                while c <= cap do c = c * 2 + 2
@@ -1059,23 +1067,17 @@ class FlatBuffer
 
        redef fun to_s: String
        do
-               var l = length
-               var a = calloc_string(l+1)
-               items.copy_to(a, l, 0, 0)
-
-               # Ensure the afterlast byte is '\0' to nul-terminated char *
-               a[length] = '\0'
-
-               return a.to_s_with_length(length)
+               return to_cstring.to_s_with_length(length)
        end
 
        redef fun to_cstring
        do
-               if real_items == null then
+               if is_dirty then
                        var new_native = calloc_string(length + 1)
                        new_native[length] = '\0'
                        items.copy_to(new_native, length, 0, 0)
                        real_items = new_native
+                       is_dirty = false
                end
                return real_items.as(not null)
        end
@@ -1116,6 +1118,7 @@ class FlatBuffer
 
        redef fun append(s)
        do
+               is_dirty = true
                var sl = s.length
                if capacity < length + sl then enlarge(length + sl)
                if s isa FlatString then