[PATCH v7 2/2] wininet: Partially implement InternetSetFilePointer

[Jason Kuo]

From: Jason Kuo

The function is implemented by manipulating read_pos and read_size or
setting cache pointer to fill read_buf if cache handle is available.
Consequently, when HTTPREQ_ReadFile is called with valid cache handle,
it will try reading data from cache after read_buf is depleted, before
continuing reading from http stream.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=26570
---
 dlls/wininet/http.c     |  5 +++
 dlls/wininet/internet.c | 86 +++++++++++++++++++++++++++++++++++++++--
 2 files changed, 88 insertions(+), 3 deletions(-)

diff --git a/dlls/wininet/http.c b/dlls/wininet/http.c
index c9d1c463982..42ead1f8c8e 100644
--- a/dlls/wininet/http.c
+++ b/dlls/wininet/http.c
@@ -3184,6 +3184,11 @@ static DWORD HTTPREQ_ReadFile(object_header_t *hdr, void *buf, DWORD size, DWORD
             req->read_pos += read;
         }

+        if(read < size && req->hCacheFile) {
+            res = ReadFile(req->hCacheFile, (char*)buf+read, size-read, &cread, NULL);
+            read += cread;
+        }
+
         if(read < size && (!read || !(flags & IRF_NO_WAIT)) && !end_of_read_data(req)) {
             LeaveCriticalSection(&req->read_section);
             INTERNET_SendCallback(&req->hdr, req->hdr.dwContext, INTERNET_STATUS_RECEIVING_RESPONSE, NULL, 0);
diff --git a/dlls/wininet/internet.c b/dlls/wininet/internet.c
index 292fd44dd8e..1920e582ab6 100644
--- a/dlls/wininet/internet.c
+++ b/dlls/wininet/internet.c
@@ -2154,14 +2154,94 @@ INTERNET_STATUS_CALLBACK WINAPI InternetSetStatusCallbackW(

/***********************************************************************
  *           InternetSetFilePointer (WININET.@)
+ * Sets read position for an open internet file.
+ *
+ * RETURNS
+ *    Current position of the file on success
+ *    INVALID_SET_FILE_POINTER on failure
  */
 DWORD WINAPI InternetSetFilePointer(HINTERNET hFile, LONG lDistanceToMove,
     PVOID pReserved, DWORD dwMoveContext, DWORD_PTR dwContext)
 {
-    FIXME("(%p %ld %p %ld %Ix): stub\n", hFile, lDistanceToMove, pReserved, dwMoveContext, dwContext);
+    DWORD pos, size, read, cread;
+    DWORD err = ERROR_INTERNET_INVALID_OPERATION, res = INVALID_SET_FILE_POINTER;
+    http_request_t *request;
+
+    TRACE("(%p %ld %p %ld %Ix)\n", hFile, lDistanceToMove, pReserved, dwMoveContext, dwContext);
+
+    request = (http_request_t*)get_handle_object(hFile);
+
+    if(request->session->appInfo->hdr.dwFlags & INTERNET_FLAG_ASYNC) {
+        FIXME("Asynchronous request not implemented\n");
+        goto lend;
+    }
+
+    if(request->hdr.dwFlags & (INTERNET_FLAG_DONT_CACHE|INTERNET_FLAG_NO_CACHE_WRITE))
+        goto lend;
+
+    switch (dwMoveContext) {
+        case FILE_BEGIN:
+            res = lDistanceToMove;
+            break;
+        case FILE_CURRENT:
+            FIXME("dwMoveContext %ld not implemented\n", dwMoveContext);
+            err = ERROR_NEGATIVE_SEEK;
+            goto lend;
+        case FILE_END:
+        default:
+            FIXME("Unhandled dwMoveContext %ld\n", dwMoveContext);
+            goto lend;
+    }

-    SetLastError(ERROR_INTERNET_INVALID_OPERATION);
-    return INVALID_SET_FILE_POINTER;
+    if(request->hCacheFile) {
+        size = GetFileSize(request->hCacheFile, NULL);
+        err = size == INVALID_FILE_SIZE ? GetLastError() : NO_ERROR;
+        if(err != NO_ERROR) {
+            ERR("GetFileSize failed with error %ld\n", err);
+            goto lend;
+        }
+        if(size < res) {
+            BYTE buf[1024];
+            BOOL ret;
+            while(size < res) {
+                ret = InternetReadFile(hFile, buf, 1024, &cread);
+                if(ret != ERROR_SUCCESS || !cread)
+                    break;
+                size = GetFileSize(request->hCacheFile, NULL);
+            }
+        }
+        pos = SetFilePointer(request->hCacheFile, lDistanceToMove, NULL, dwMoveContext);
+        err = pos == INVALID_SET_FILE_POINTER ? GetLastError() : NO_ERROR;
+        if(err != NO_ERROR) {
+            ERR("SetFilePointer failed with error %ld\n", err);
+            goto lend;
+        }
+        EnterCriticalSection(&request->read_section);
+        read = min(READ_BUFFER_SIZE, size-pos);
+        if(ReadFile(request->hCacheFile, request->read_buf, read, &cread, NULL)) {
+            request->read_size = cread;
+            request->read_pos = 0;
+        }
+        LeaveCriticalSection(&request->read_section);
+    }
+    else {
+        if(!request->contentLength)
+            goto lend;
+        EnterCriticalSection(&request->read_section);
+        size = request->read_pos + request->read_size;
+        pos = size - request->contentLength;
+        request->read_pos = min(size, pos + res);
+        request->read_size = size - request->read_pos;
+        LeaveCriticalSection(&request->read_section);
+    }
+
+lend:
+    if(res == INVALID_SET_FILE_POINTER)
+        SetLastError(err);
+    TRACE("returning %ld\n", res);
+    if(request)
+        WININET_Release( &request->hdr );
+    return res;
 }

/***********************************************************************