Fix #80061: Copying large files may have suboptimal performance

main/streams/php_stream_mmap.h

@@ -58,6 +58,8 @@ typedef struct {
 
 #define PHP_STREAM_MMAP_ALL 0
 
+#define PHP_STREAM_MMAP_MAX (512 * 1024 * 1024)
+
 #define php_stream_mmap_supported(stream)	(_php_stream_set_option((stream), PHP_STREAM_OPTION_MMAP_API, PHP_STREAM_MMAP_SUPPORTED, NULL) == 0 ? 1 : 0)
 
 /* Returns 1 if the stream in its current state can be memory mapped,

main/streams/plain_wrapper.c

@@ -826,6 +826,11 @@ static int php_stdiop_set_option(php_stream *stream, int option, int value, void
 							delta = (DWORD)range->offset - loffs;
 						}
 
+						/* MapViewOfFile()ing zero bytes would map to the end of the file; match *nix behavior instead */
+						if (range->length + delta == 0) {
+							return PHP_STREAM_OPTION_RETURN_ERR;
+						}
+
 						data->last_mapped_addr = MapViewOfFile(data->file_mapping, acc, 0, loffs, range->length + delta);
 
 						if (data->last_mapped_addr) {

main/streams/streams.c

@@ -1573,29 +1573,48 @@ PHPAPI int _php_stream_copy_to_stream_ex(php_stream *src, php_stream *dest, size
 
 	if (php_stream_mmap_possible(src)) {
 		char *p;
-		size_t mapped;
 
-		p = php_stream_mmap_range(src, php_stream_tell(src), maxlen, PHP_STREAM_MAP_MODE_SHARED_READONLY, &mapped);
+		do {
+			size_t chunk_size = (maxlen == 0 || maxlen > PHP_STREAM_MMAP_MAX) ? PHP_STREAM_MMAP_MAX : maxlen;
+			size_t mapped;
 
-		if (p) {
-			ssize_t didwrite = php_stream_write(dest, p, mapped);
-			if (didwrite < 0) {
-				*len = 0;
-				return FAILURE;
-			}
+			p = php_stream_mmap_range(src, php_stream_tell(src), chunk_size, PHP_STREAM_MAP_MODE_SHARED_READONLY, &mapped);
+
+			if (p) {
+				ssize_t didwrite;
+
+				if (php_stream_seek(src, mapped, SEEK_CUR) != 0) {
+					php_stream_mmap_unmap(src);
+					break;
+				}
+
+				didwrite = php_stream_write(dest, p, mapped);
+				if (didwrite < 0) {
+					*len = haveread;
+					return FAILURE;
+				}
 
-			php_stream_mmap_unmap_ex(src, mapped);
+				php_stream_mmap_unmap(src);
 
-			*len = didwrite;
+				*len = haveread += didwrite;
 
-			/* we've got at least 1 byte to read
-			 * less than 1 is an error
-			 * AND read bytes match written */
-			if (mapped > 0 && mapped == didwrite) {
-				return SUCCESS;
+				/* we've got at least 1 byte to read
+				 * less than 1 is an error
+				 * AND read bytes match written */
+				if (mapped == 0 || mapped != didwrite) {
+					return FAILURE;
+				}
+				if (mapped < chunk_size) {
+					return SUCCESS;
+				}
+				if (maxlen != 0) {
+					maxlen -= mapped;
+					if (maxlen == 0) {
+						return SUCCESS;
+					}
+				}
 			}
-			return FAILURE;
-		}
+		} while (p);
 	}
 
 	while(1) {