+Comments about AllocationSize/FileSize/ValidDataLength meaning.

diff --git a/src/libcaptive/cc/sharedcachemap-priv.h b/src/libcaptive/cc/sharedcachemap-priv.h
index 0d69717..084948e 100644 (file)
--- a/src/libcaptive/cc/sharedcachemap-priv.h
+++ b/src/libcaptive/cc/sharedcachemap-priv.h
@@ -44,8 +44,20 @@ struct _CaptiveSharedCacheMapObject {
        FILE_OBJECT *FileObject;
        SECTION_OBJECT_POINTERS *SectionObjectPointers;
        /* ValidDataLength<=FileSize<=AllocationSize */
+       /* 'AllocationSize' sets the mmap(2)ed area of buffers of this SharedCacheMap.
+        * We must reallocate this area if 'AllocationSize' changes and in such case
+        * there must exist no map-Bcb or pin-Bcbs for it.
+        * We would cope with 'buffer' change with existing Bcbs but W32 client could not.
+        */
        guint64 AllocationSize; /* ==CC_FILE_SIZES.AllocationSize.QuadPart */
+       /* We generally check against CAPTIVE_ROUND_UP64(FileSize,PAGE_SIZE)
+        * as the offsets are usually PAGE_SIZE aligned due to pin-Bcb expectations.
+        */
        guint64 FileSize;       /* ==CC_FILE_SIZES.FileSize.QuadPart */
+       /* We use 'FileSize' instead of 'ValidDataLength' as I assume W32
+        * automatically increases 'ValidDataLength' during Cache Manager write operations.
+        * We do not increase it and therefore it is mostly useless for us.
+        */
        guint64 ValidDataLength;        /* ==CC_FILE_SIZES.ValidDataLength.QuadPart */
        CACHE_MANAGER_CALLBACKS CallBacks;
        VOID *LazyWriterContext;