1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef NET_BASE_MIME_SNIFFER_H__ 6 #define NET_BASE_MIME_SNIFFER_H__ 7 8 #include <string> 9 10 #include "net/base/net_export.h" 11 12 class GURL; 13 14 namespace net { 15 16 // The maximum number of bytes used by any internal mime sniffing routine. May 17 // be useful for callers to determine an efficient buffer size to pass to 18 // |SniffMimeType|. 19 // This must be updated if any internal sniffing routine needs more bytes. 20 const int kMaxBytesToSniff = 1024; 21 22 // Examine the URL and the mime_type and decide whether we should sniff a 23 // replacement mime type from the content. 24 // 25 // @param url The URL from which we obtained the content. 26 // @param mime_type The current mime type, e.g. from the Content-Type header. 27 // @return Returns true if we should sniff the mime type. 28 NET_EXPORT bool ShouldSniffMimeType(const GURL& url, 29 const std::string& mime_type); 30 31 // Guess a mime type from the first few bytes of content an its URL. Always 32 // assigns |result| with its best guess of a mime type. 33 // 34 // @param content A buffer containing the bytes to sniff. 35 // @param content_size The number of bytes in the |content| buffer. 36 // @param url The URL from which we obtained this content. 37 // @param type_hint The current mime type, e.g. from the Content-Type header. 38 // @param result Address at which to place the sniffed mime type. 39 // @return Returns true if we have enough content to guess the mime type. 40 NET_EXPORT bool SniffMimeType(const char* content, size_t content_size, 41 const GURL& url, const std::string& type_hint, 42 std::string* result); 43 44 // Attempt to identify a MIME type from the first few bytes of content only. 45 // Uses a bigger set of media file searches than |SniffMimeType()|. 46 // If finds a match, fills in |result| and returns true, 47 // otherwise returns false. 48 // 49 // The caller should understand the security ramifications of trusting 50 // uncontrolled data before accepting the results of this function. 51 // 52 // @param content A buffer containing the bytes to sniff. 53 // @param content_size The number of bytes in the |content| buffer. 54 // @param result Address at which to place the sniffed mime type. 55 // @return Returns true if a MIME type match was found. 56 NET_EXPORT bool SniffMimeTypeFromLocalData(const char* content, 57 size_t content_size, 58 std::string* result); 59 60 } // namespace net 61 62 #endif // NET_BASE_MIME_SNIFFER_H__ 63