Changeset 31526 in vbox for trunk/include/iprt

Timestamp:

Aug 10, 2010 12:03:09 PM (14 years ago)

Author:

vboxsync

Message:

iprt/sg.h: Made RTSgBufMapToNative a bit safer and fixed some left over variable refs.

File:

• trunk/include/iprt/sg.h (modified) (1 diff)

trunk/include/iprt/sg.h

@@ -205 +205 @@
 
 /**
- * Maps the given S/G buffer to a segment array of another type
- * (for example to iovec on Posix or WSABUF on Windows).
- *
- * @param   paMapped    Where to store the pointer to the start of the native array or NULL.
- *                      The memory needs to be freed with RTMemTmpFree().
+ * Maps the given S/G buffer to a segment array of another type (for example to
+ * iovec on POSIX or WSABUF on Windows).
+ *
+ * @param   paMapped    Where to store the pointer to the start of the native
+ *                      array or NULL.  The memory needs to be freed with
+ *                      RTMemTmpFree().
  * @param   pSgBuf      The S/G buffer to map.
  * @param   Struct      Struct used as the destination.
- * @param   pvBuf       Name of the field holding the pointer to a buffer.
+ * @param   pvBufField  Name of the field holding the pointer to a buffer.
  * @param   TypeBufPtr  Type of the buffer pointer.
- * @param   cbBuf       Name of the field holding the size of the buffer.
+ * @param   cbBufField  Name of the field holding the size of the buffer.
  * @param   TypeBufSize Type of the field for the buffer size.
- * @param   cSegsMapped Where to store the number of segments the native array has.
- *
- * @note This operation maps the whole S/G buffer starting at the current internal position.
- *       The internal buffer position is unchanged by this operation.
- *
- * @remark Usage is a bit ugly but saves a few lines of duplicated code somewhere else and makes it possible to
- *         keep the S/G buffer members private without going through RTSgBufSegArrayCreate() first.
- */
-#define RTSgBufMapToNative(paMapped, pSgBuf, Struct, pvBuf, TypeBufPtr, cbBuf, TypeBufSize, cSegsMapped) \
-    do                                                                                        \
-    {                                                                                         \
-        AssertCompileMemberSize(Struct, pvBuf, RT_SIZEOFMEMB(RTSGSEG, pvSeg));                \
-        /*AssertCompile(RT_SIZEOFMEMB(Struct, cbBuf) >=  RT_SIZEOFMEMB(RTSGSEG, cbSeg));*/    \
-        cSegsMapped = pSgBuf->cSegs - pSgBuf->idxSeg;                                         \
-                                                                                              \
-        paMapped = NULL;                                                                      \
-                                                                                              \
-        /* We need room for at least one segment. */                                          \
-        if (pSgBuf->cSegs == pSgBuf->idxSeg)                                                  \
-            cSegsMapped++;                                                                    \
-                                                                                              \
-        paMapped = (Struct *)RTMemTmpAllocZ(cSegsMapped * sizeof(Struct));                    \
-        if (paMapped)                                                                         \
-        {                                                                                     \
+ * @param   cSegsMapped Where to store the number of segments the native array
+ *                      has.
+ *
+ * @note    This operation maps the whole S/G buffer starting at the current
+ *          internal position.  The internal buffer position is unchanged by
+ *          this operation.
+ *
+ * @remark  Usage is a bit ugly but saves a few lines of duplicated code
+ *          somewhere else and makes it possible to keep the S/G buffer members
+ *          private without going through RTSgBufSegArrayCreate() first.
+ */
+#define RTSgBufMapToNative(paMapped, pSgBuf, Struct, pvBufField, TypeBufPtr, cbBufField, TypeBufSize, cSegsMapped) \
+    do \
+    { \
+        AssertCompileMemberSize(Struct, pvBufField, RT_SIZEOFMEMB(RTSGSEG, pvSeg)); \
+        /*AssertCompile(RT_SIZEOFMEMB(Struct, cbBufField) >=  RT_SIZEOFMEMB(RTSGSEG, cbSeg));*/ \
+        (cSegsMapped) = (pSgBuf)->cSegs - (pSgBuf)->idxSeg; \
+        \
+        /* We need room for at least one segment. */ \
+        if ((pSgBuf)->cSegs == (pSgBuf)->idxSeg) \
+            (cSegsMapped)++; \
+        \
+        (paMapped) = (Struct *)RTMemTmpAllocZ((cSegsMapped) * sizeof(Struct)); \
+        if ((paMapped)) \
+        { \
             /* The first buffer is special because we could be in the middle of a segment. */ \
-            paMapped[0].pvBuf = (TypeBufPtr)pSgBuf->pvSegCur;                                 \
-            paMapped[0].cbBuf = (TypeBufSize)pSgBuf->cbSegLeft;                               \
-                                                                                              \
-            for (unsigned i = 1; i < cSegsMapped; i++)                                        \
-            {                                                                                 \
-                paMsg[i].pvBuf = (TypeBufPtr)pSgBuf->paSegs[pSgBuf->idxSeg + i].pvSeg;        \
-                paMsg[i].cbBuf = (TypeBufSize)pSgBuf->paSegs[pSgBuf->idxSeg + i].cbSeg;       \
-            }                                                                                 \
-        }                                                                                     \
-    }                                                                                         \
-    while (0)
+            (paMapped)[0].pvBufField = (TypeBufPtr)(pSgBuf)->pvSegCur; \
+            (paMapped)[0].cbBufField = (TypeBufSize)(pSgBuf)->cbSegLeft; \
+            \
+            for (unsigned i = 1; i < (cSegsMapped); i++) \
+            { \
+                (paMapped)[i].pvBufField = (TypeBufPtr)(pSgBuf)->paSegs[(pSgBuf)->idxSeg + i].pvSeg; \
+                (paMapped)[i].cbBufField = (TypeBufSize)(pSgBuf)->paSegs[(pSgBuf)->idxSeg + i].cbSeg; \
+            } \
+        } \
+    } while (0)
 
 RT_C_DECLS_END