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 12class GURL; 13 14namespace 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. 20const 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. 28NET_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. 40NET_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. 56NET_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