Source/WebKitLegacy/mac/Misc/WebNSDataExtras.mm - external/github.com/WebKit/webkit - Git at Google

 /*
  * Copyright (C) 2005-2018 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */

 #import <WebKitLegacy/WebNSDataExtras.h>

 #import <wtf/Assertions.h>

 @implementation NSData (WebNSDataExtras)

 - (NSString *)_webkit_guessedMIMETypeForXML
 {
     NSUInteger length = [self length];
     const UInt8* bytes = static_cast<const UInt8*>([self bytes]);

 #define CHANNEL_TAG_LENGTH 7

     const char* p = byteCast<char>(bytes);
     int remaining = std::min<NSUInteger>(length, WEB_GUESS_MIME_TYPE_PEEK_LENGTH) - (CHANNEL_TAG_LENGTH - 1);

     BOOL foundRDF = false;

     while (remaining > 0) {
         // Look for a "<".
         const char* hit = static_cast<const char*>(memchr(p, '<', remaining));
         if (!hit)
             break;

         // We are trying to identify RSS or Atom. RSS has a top-level
         // element of either <rss> or <rdf>. However, there are
         // non-RSS RDF files, so in the case of <rdf> we further look
         // for a <channel> element. In the case of an Atom file, a
         // top-level <feed> element is all we need to see. Only tags
         // starting with <? or <! can precede the root element. We
         // bail if we don't find an <rss>, <feed> or <rdf> element
         // right after those.

         if (foundRDF) {
             if (!strncasecmp(hit, "<channel", strlen("<channel")))
                 return @"application/rss+xml";
         } else if (!strncasecmp(hit, "<rdf", strlen("<rdf")))
             foundRDF = TRUE;
         else if (!strncasecmp(hit, "<rss", strlen("<rss")))
             return @"application/rss+xml";
         else if (!strncasecmp(hit, "<feed", strlen("<feed")))
             return @"application/atom+xml";
         else if (strncasecmp(hit, "<?", strlen("<?")) && strncasecmp(hit, "<!", strlen("<!")))
             return nil;

         // Skip the "<" and continue.
         remaining -= (hit + 1) - p;
         p = hit + 1;
     }

     return nil;
 }

 - (NSString *)_webkit_guessedMIMEType
 {
 #define JPEG_MAGIC_NUMBER_LENGTH 4
 #define SCRIPT_TAG_LENGTH 7
 #define TEXT_HTML_LENGTH 9
 #define VCARD_HEADER_LENGTH 11
 #define VCAL_HEADER_LENGTH 15

     NSString *MIMEType = [self _webkit_guessedMIMETypeForXML];
     if ([MIMEType length])
         return MIMEType;

     NSUInteger length = [self length];
     const char* bytes = static_cast<const char*>([self bytes]);

     const char* p = bytes;
     int remaining = std::min<NSUInteger>(length, WEB_GUESS_MIME_TYPE_PEEK_LENGTH) - (SCRIPT_TAG_LENGTH - 1);
     while (remaining > 0) {
         // Look for a "<".
         const char* hit = static_cast<const char*>(memchr(p, '<', remaining));
         if (!hit)
             break;

         // If we found a "<", look for "<html>" or "<a " or "<script".
         if (!strncasecmp(hit, "<html>", strlen("<html>"))
             || !strncasecmp(hit, "<a ", strlen("<a "))
             || !strncasecmp(hit, "<script", strlen("<script"))
             || !strncasecmp(hit, "<title>", strlen("<title>"))) {
             return @"text/html";
         }

         // Skip the "<" and continue.
         remaining -= (hit + 1) - p;
         p = hit + 1;
     }

     // Test for a broken server which has sent the content type as part of the content.
     // This code could be improved to look for other mime types.
     p = bytes;
     remaining = std::min<NSUInteger>(length, WEB_GUESS_MIME_TYPE_PEEK_LENGTH) - (TEXT_HTML_LENGTH - 1);
     while (remaining > 0) {
         // Look for a "t" or "T".
         const char* hit = nullptr;
         const char* lowerhit = static_cast<const char*>(memchr(p, 't', remaining));
         const char* upperhit = static_cast<const char*>(memchr(p, 'T', remaining));
         if (!lowerhit && !upperhit)
             break;

         if (!lowerhit)
             hit = upperhit;
         else if (!upperhit)
             hit = lowerhit;
         else
             hit = std::min<const char*>(lowerhit, upperhit);

         // If we found a "t/T", look for "text/html".
         if (!strncasecmp(hit, "text/html", TEXT_HTML_LENGTH))
             return @"text/html";

         // Skip the "t/T" and continue.
         remaining -= (hit + 1) - p;
         p = hit + 1;
     }

     if ((length >= VCARD_HEADER_LENGTH) && !strncmp(bytes, "BEGIN:VCARD", VCARD_HEADER_LENGTH))
         return @"text/vcard";
     if ((length >= VCAL_HEADER_LENGTH) && !strncmp(bytes, "BEGIN:VCALENDAR", VCAL_HEADER_LENGTH))
         return @"text/calendar";

     // Test for plain text.
     NSUInteger i;
     for (i = 0; i < length; ++i) {
         char c = bytes[i];
         if ((c < 0x20 || c > 0x7E) && (c != '\t' && c != '\r' && c != '\n'))
             break;
     }
     if (i == length) {
         // Didn't encounter any bad characters, looks like plain text.
         return @"text/plain";
     }

     // Looks like this is a binary file.

     // Sniff for the JPEG magic number.
     if ((length >= JPEG_MAGIC_NUMBER_LENGTH) && !strncmp(bytes, "\xFF\xD8\xFF\xE0", JPEG_MAGIC_NUMBER_LENGTH))
         return @"image/jpeg";

 #undef JPEG_MAGIC_NUMBER_LENGTH
 #undef SCRIPT_TAG_LENGTH
 #undef TEXT_HTML_LENGTH
 #undef VCARD_HEADER_LENGTH
 #undef VCAL_HEADER_LENGTH

     return nil;
 }

 - (BOOL)_web_isCaseInsensitiveEqualToCString:(const char *)string
 {
     ASSERT(string);

     const char* bytes = static_cast<const char*>([self bytes]);
     return !strncasecmp(bytes, string, [self length]);
 }

 @end
	/*
	* Copyright (C) 2005-2018 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#import <WebKitLegacy/WebNSDataExtras.h>

	#import <wtf/Assertions.h>

	@implementation NSData (WebNSDataExtras)

	- (NSString *)_webkit_guessedMIMETypeForXML
	{
	NSUInteger length = [self length];
	const UInt8* bytes = static_cast<const UInt8*>([self bytes]);

	#define CHANNEL_TAG_LENGTH 7

	const char* p = byteCast<char>(bytes);
	int remaining = std::min<NSUInteger>(length, WEB_GUESS_MIME_TYPE_PEEK_LENGTH) - (CHANNEL_TAG_LENGTH - 1);

	BOOL foundRDF = false;

	while (remaining > 0) {
	// Look for a "<".
	const char* hit = static_cast<const char*>(memchr(p, '<', remaining));
	if (!hit)
	break;

	// We are trying to identify RSS or Atom. RSS has a top-level
	// element of either <rss> or <rdf>. However, there are
	// non-RSS RDF files, so in the case of <rdf> we further look
	// for a <channel> element. In the case of an Atom file, a
	// top-level <feed> element is all we need to see. Only tags
	// starting with <? or <! can precede the root element. We
	// bail if we don't find an <rss>, <feed> or <rdf> element
	// right after those.

	if (foundRDF) {
	if (!strncasecmp(hit, "<channel", strlen("<channel")))
	return @"application/rss+xml";
	} else if (!strncasecmp(hit, "<rdf", strlen("<rdf")))
	foundRDF = TRUE;
	else if (!strncasecmp(hit, "<rss", strlen("<rss")))
	return @"application/rss+xml";
	else if (!strncasecmp(hit, "<feed", strlen("<feed")))
	return @"application/atom+xml";
	else if (strncasecmp(hit, "<?", strlen("<?")) && strncasecmp(hit, "<!", strlen("<!")))
	return nil;

	// Skip the "<" and continue.
	remaining -= (hit + 1) - p;
	p = hit + 1;
	}

	return nil;
	}

	- (NSString *)_webkit_guessedMIMEType
	{
	#define JPEG_MAGIC_NUMBER_LENGTH 4
	#define SCRIPT_TAG_LENGTH 7
	#define TEXT_HTML_LENGTH 9
	#define VCARD_HEADER_LENGTH 11
	#define VCAL_HEADER_LENGTH 15

	NSString *MIMEType = [self _webkit_guessedMIMETypeForXML];
	if ([MIMEType length])
	return MIMEType;

	NSUInteger length = [self length];
	const char* bytes = static_cast<const char*>([self bytes]);

	const char* p = bytes;
	int remaining = std::min<NSUInteger>(length, WEB_GUESS_MIME_TYPE_PEEK_LENGTH) - (SCRIPT_TAG_LENGTH - 1);
	while (remaining > 0) {
	// Look for a "<".
	const char* hit = static_cast<const char*>(memchr(p, '<', remaining));
	if (!hit)
	break;

	// If we found a "<", look for "<html>" or "<a " or "<script".
	if (!strncasecmp(hit, "<html>", strlen("<html>"))
	\|\| !strncasecmp(hit, "<a ", strlen("<a "))
	\|\| !strncasecmp(hit, "<script", strlen("<script"))
	\|\| !strncasecmp(hit, "<title>", strlen("<title>"))) {
	return @"text/html";
	}

	// Skip the "<" and continue.
	remaining -= (hit + 1) - p;
	p = hit + 1;
	}

	// Test for a broken server which has sent the content type as part of the content.
	// This code could be improved to look for other mime types.
	p = bytes;
	remaining = std::min<NSUInteger>(length, WEB_GUESS_MIME_TYPE_PEEK_LENGTH) - (TEXT_HTML_LENGTH - 1);
	while (remaining > 0) {
	// Look for a "t" or "T".
	const char* hit = nullptr;
	const char* lowerhit = static_cast<const char*>(memchr(p, 't', remaining));
	const char* upperhit = static_cast<const char*>(memchr(p, 'T', remaining));
	if (!lowerhit && !upperhit)
	break;

	if (!lowerhit)
	hit = upperhit;
	else if (!upperhit)
	hit = lowerhit;
	else
	hit = std::min<const char*>(lowerhit, upperhit);

	// If we found a "t/T", look for "text/html".
	if (!strncasecmp(hit, "text/html", TEXT_HTML_LENGTH))
	return @"text/html";

	// Skip the "t/T" and continue.
	remaining -= (hit + 1) - p;
	p = hit + 1;
	}

	if ((length >= VCARD_HEADER_LENGTH) && !strncmp(bytes, "BEGIN:VCARD", VCARD_HEADER_LENGTH))
	return @"text/vcard";
	if ((length >= VCAL_HEADER_LENGTH) && !strncmp(bytes, "BEGIN:VCALENDAR", VCAL_HEADER_LENGTH))
	return @"text/calendar";

	// Test for plain text.
	NSUInteger i;
	for (i = 0; i < length; ++i) {
	char c = bytes[i];
	if ((c < 0x20 \|\| c > 0x7E) && (c != '\t' && c != '\r' && c != '\n'))
	break;
	}
	if (i == length) {
	// Didn't encounter any bad characters, looks like plain text.
	return @"text/plain";
	}

	// Looks like this is a binary file.

	// Sniff for the JPEG magic number.
	if ((length >= JPEG_MAGIC_NUMBER_LENGTH) && !strncmp(bytes, "\xFF\xD8\xFF\xE0", JPEG_MAGIC_NUMBER_LENGTH))
	return @"image/jpeg";

	#undef JPEG_MAGIC_NUMBER_LENGTH
	#undef SCRIPT_TAG_LENGTH
	#undef TEXT_HTML_LENGTH
	#undef VCARD_HEADER_LENGTH
	#undef VCAL_HEADER_LENGTH

	return nil;
	}

	- (BOOL)_web_isCaseInsensitiveEqualToCString:(const char *)string
	{
	ASSERT(string);

	const char* bytes = static_cast<const char*>([self bytes]);
	return !strncasecmp(bytes, string, [self length]);
	}

	@end