[reactos] 02/02: [CMD] Do not use an intermediate buffer when reading lines from batch files

[Jérôme Gardou]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=aae161d06184383e3ed06…

commit aae161d06184383e3ed06a85918c02ef47f77526
Author:     Jérôme Gardou <jerome.gardou(a)reactos.org>
AuthorDate: Wed Jun 23 16:26:50 2021 +0200
Commit:     Jérôme Gardou <zefklop(a)users.noreply.github.com>
CommitDate: Thu Jun 24 15:03:36 2021 +0200

    [CMD] Do not use an intermediate buffer when reading lines from batch files
    
    This is easier on the heap and improves cmd:batch winetest nicely
---
 base/shell/cmd/batch.c | 41 ++++++++++++-----------------------------
 1 file changed, 12 insertions(+), 29 deletions(-)

diff --git a/base/shell/cmd/batch.c b/base/shell/cmd/batch.c
index 8fc6bf8466e..f20028af23f 100644
--- a/base/shell/cmd/batch.c
+++ b/base/shell/cmd/batch.c
@@ -75,7 +75,6 @@ BOOL bEcho = TRUE;  /* The echo flag */
 /* Buffer for reading Batch file lines */
 TCHAR textline[BATCH_BUFFSIZE];
 
-
 /*
  * Returns a pointer to the n'th parameter of the current batch file.
  * If no such parameter exists returns pointer to empty string.
@@ -527,47 +526,31 @@ VOID AddBatchRedirection(REDIRECTION **RedirList)
  */
 BOOL BatchGetString(LPTSTR lpBuffer, INT nBufferLength)
 {
-    LPSTR lpString;
     INT len = 0;
-#ifdef _UNICODE
-    lpString = cmd_alloc(nBufferLength);
-    if (!lpString)
-    {
-        WARN("Cannot allocate memory for lpString\n");
-        error_out_of_memory();
-        return FALSE;
-    }
-#else
-    lpString = lpBuffer;
-#endif
+
     /* read all chars from memory until a '\n' is encountered */
     if (bc->mem)
     {
-        for (; (bc->mempos < bc->memsize  &&  len <
(nBufferLength-1)); len++)
-        { 
-            lpString[len] = bc->mem[bc->mempos++];
-            if (lpString[len] == '\n' )
+        for (; ((bc->mempos + len) < bc->memsize  &&  len <
(nBufferLength-1)); len++)
+        {
+#ifndef _UNICODE
+            lpBuffer[len] = bc->mem[bc->mempos + len];
+#endif
+            if (bc->mem[bc->mempos + len] == '\n')
             {
                 len++;
                 break;
             }
         }
-    }
-
-    if (!len)
-    {
 #ifdef _UNICODE
-        cmd_free(lpString);
+        nBufferLength = MultiByteToWideChar(OutputCodePage, 0,
&bc->mem[bc->mempos], len, lpBuffer, nBufferLength);
+        lpBuffer[nBufferLength] = L'\0';
+        lpBuffer[len] = '\0';
 #endif
-        return FALSE;
+        bc->mempos += len;
     }
 
-    lpString[len++] = '\0';
-#ifdef _UNICODE
-    MultiByteToWideChar(OutputCodePage, 0, lpString, -1, lpBuffer, len);
-    cmd_free(lpString);
-#endif
-    return TRUE;
+    return len != 0;
 }
 
 /*