#include <opennurbs_file_utilities.h>

Public Types
enum	CompareResult : unsigned char { CompareResult::Unset = 0, CompareResult::EqualContent = 1, CompareResult::DifferentContent = 2, CompareResult::DifferentContentFileIsOlder = 3, CompareResult::ContentDifferentFileIsNewer = 4, CompareResult::FileDoesNotExist = 5, CompareResult::FileSystemFailure = 6 }
	ON_ContentHash::Compare are the possible results of calling ON_ContentHash::CompareFile(). More...

Public Member Functions
	ON_ContentHash ()=default

	ON_ContentHash (const ON_ContentHash &)=default

	~ON_ContentHash ()=default

ON__UINT64	ByteCount () const

ON_ContentHash::CompareResult	Compare (const wchar_t *file_path, bool bFastTest) const
	Compare the information used to set this content hash with the contents of the file. More...

ON_ContentHash::CompareResult	Compare (ON_ContentHash file_content_hash) const
	Compare the byte count and SHA-1 content hash. More...

ON_SHA1_Hash	ContentHash () const

ON__UINT64	ContentLastModifiedTime () const

void	Dump (class ON_TextLog &text_log) const

bool	EqualFileNameSizeAndTime (const wchar_t *filename) const

ON__UINT64	HashCalculationTime () const

bool	IsNotSet () const

bool	IsSameBufferContent (const void *buffer, size_t byte_count) const
	Test a buffer to see if it has a matching size and SHA-1 hash. More...

bool	IsSameFileContent (FILE *fp) const
	Test a file to see if it has a matching size and SHA-1 hash. Paramters: fp - [in] pointer to file opened with ON::OpenFile(...,"rb") bSkipTimeCheck - [in] if true, the time of last modification is not checked. More...

bool	IsSameFileContent (const wchar_t *filename) const
	Test a file to see if it has a matching size and SHA-1 content hash. Paramters: filename - [in] More...

bool	IsSameFileContent (const char *filename) const

bool	IsSet () const

ON_SHA1_Hash	NameHash () const

ON_ContentHash &	operator= (const ON_ContentHash &)=default

bool	Read (class ON_BinaryArchive &archive)

bool	Write (class ON_BinaryArchive &archive) const

Static Public Member Functions
static int	Compare (const ON_ContentHash &a, const ON_ContentHash &b)
	Compares all fields More...

static int	CompareContent (const ON_ContentHash &a, const ON_ContentHash &b)
	Compares content byte count and content SHA-1 More...

static ON_ContentHash::CompareResult	CompareResultFromUnsigned (unsigned int compare_result_as_unsigned)

static ON_ContentHash	Create (ON_SHA1_Hash sha1_name_hash, ON__UINT64 byte_count, ON_SHA1_Hash sha1_content_hash, ON__UINT64 hash_time, ON__UINT64 content_last_modified_time)

static ON_ContentHash	CreateFromBuffer (ON_SHA1_Hash sha1_name_hash, const void *buffer, size_t byte_count)

static ON_ContentHash	CreateFromFile (ON_SHA1_Hash sha1_file_name_hash, FILE *fp)

static ON_ContentHash	CreateFromFile (const wchar_t *filename)

static ON_ContentHash	CreateFromFile (const char *filename)

static bool	DifferentContent (const ON_ContentHash &a, const ON_ContentHash &b)

static bool	EqualContent (const ON_ContentHash &a, const ON_ContentHash &b)

Static Public Attributes
static const ON_ContentHash	Unset

Member Enumeration Documentation

◆ CompareResult

enum ON_ContentHash::CompareResult : unsigned char

strong

ON_ContentHash::Compare are the possible results of calling ON_ContentHash::CompareFile().

Enumerator
Unset	Not set. This value is never returned by ON_ContentHash::CheckFile().
EqualContent	File exists and its size and content matches the information used to set the content hash.
DifferentContent	File exists and its size or content differs from the information used to set the content hash. Unable to reliably determine which is newer.
DifferentContentFileIsOlder	File exists and its size or content differs from the information used to set the content hash. The file's laste modified time is older than ContentLastModifiedTime().
ContentDifferentFileIsNewer	File exists and its size or content differs from the information used to set the content hash. The file's last modified time is newer than ContentLastModifiedTime().
FileDoesNotExist	File does not exist.
FileSystemFailure	File cannot be opened, read, or some other file system issue prevents checking.

Constructor & Destructor Documentation

◆ ON_ContentHash() [1/2]

ON_ContentHash::ON_ContentHash ( )

default

◆ ~ON_ContentHash()

ON_ContentHash::~ON_ContentHash ( )

default

◆ ON_ContentHash() [2/2]

ON_ContentHash::ON_ContentHash ( const ON_ContentHash & )

default

Member Function Documentation

◆ ByteCount()

ON__UINT64 ON_ContentHash::ByteCount ( ) const

Returns: Number of bytes in the content (typically a file or buffer).

◆ Compare() [1/3]

ON_ContentHash::CompareResult ON_ContentHash::Compare	(	const wchar_t *	file_path,
		bool	bFastTest
	)		const

Compare the information used to set this content hash with the contents of the file.

Parameters

file_path [in]

bFastCompare [in] If bFastCompare is true and the file_path, create time, last modified time, and size exactly match the values in ON_ContentHash, then ON_ContentHash::CompareResult::EqualContent is returned without performing the expensive SHA1 test on the file's content. If bFastCompare is false, the SHA-1 hash of the file's content will be calculated and compared before ON_ContentHash::CompareResult::EqualContent is returned.

Returns: Result of compare test as a ON_ContentHash::CompareResult enum. ON_ContentHash::CompareResult::DifferentContentFileIsOlder means file_path content is different and older than "this". ON_ContentHash::CompareResult::DifferentContentFileIsNewer means file_path content is different and newer than "this".

◆ Compare() [2/3]

ON_ContentHash::CompareResult ON_ContentHash::Compare ( ON_ContentHash file_content_hash ) const

Compare the byte count and SHA-1 content hash.

Parameters

file_content_hash [in] ON_ContentHash to compare against this one.

Returns: Result of compare test as a ON_ContentHash::CompareResult enum. ON_ContentHash::CompareResult::DifferentContentFileIsOlder means file_content_hash is different and older than "this". ON_ContentHash::CompareResult::DifferentContentFileIsNewer means file_content_hash is different and newer than "this".

◆ Compare() [3/3]

static int ON_ContentHash::Compare	(	const ON_ContentHash &	a,
		const ON_ContentHash &	b
	)

static

Compares all fields

◆ CompareContent()

static int ON_ContentHash::CompareContent	(	const ON_ContentHash &	a,
		const ON_ContentHash &	b
	)

static

Compares content byte count and content SHA-1

◆ CompareResultFromUnsigned()

static ON_ContentHash::CompareResult ON_ContentHash::CompareResultFromUnsigned ( unsigned int compare_result_as_unsigned )

static

◆ ContentHash()

ON_SHA1_Hash ON_ContentHash::ContentHash ( ) const

Returns: SHA-1 hash of the content (typically a buffer or file).

◆ ContentLastModifiedTime()

ON__UINT64 ON_ContentHash::ContentLastModifiedTime ( ) const

Returns

Time the hashed content was last modifed in seconds since January 1, 1970 UCT. 0 is returned if this time is not known.

This time should be used for important decisions as a last resort.

When hash values differ, this time may be considered to which content is newer (or most recently copied).

Unfortunately, in many cases this time is often unknown and incorrectly set. For example, some file systems set the last modified time of a copy of an "old" file to the time the copy was created. Thus a copy of "old" content may appear to be newer than "new" content that has not been copied.

◆ Create()

static ON_ContentHash ON_ContentHash::Create	(	ON_SHA1_Hash	sha1_name_hash,
		ON__UINT64	byte_count,
		ON_SHA1_Hash	sha1_content_hash,
		ON__UINT64	hash_time,
		ON__UINT64	content_last_modified_time
	)

static

Parameters

sha1_name_hash	[in] The SHA-1 hash of the name (typically a full path file name). When the content is identified by a file name in a file system, use ON_SHA1_Hash::FileSystemPathHash() to calculate this value.
byte_count	[in] number of bytes in the content.
sha1_content_hash	[in] The SHA-1 hash of the content (typically a buffer or file). You may use ON_SHA1_Has::FileContentHash() or ON_SHA1_Hash::BufferContentHash() to calculate this value.
hash_time	[in] The time the sha1_hash was calculated in seconds since January 1, 1970 UCT. If 0 is passed in, the current time is used.
content_last_modified_time	[in] Pass 0 if not known. The time the hashed information that was last modifed in seconds since January 1, 1970 UCT. If content_last_modified_time > hash_time, then 0 is used.

Returns: An ON_ContentHash with size and SHA-1 hash and times set from the parameters,

◆ CreateFromBuffer()

static ON_ContentHash ON_ContentHash::CreateFromBuffer	(	ON_SHA1_Hash	sha1_name_hash,
		const void *	buffer,
		size_t	byte_count
	)

static

Parameters

sha1_name_hash	[in] A SHA-1 hash of the name associated with this content. If the buffer has no name, pass ON_SHA1_Hash::ZeroDigest. If the buffer has an empty name, pass ON_SHA1_Hash::EmptyContentHash.
buffer	[in]
byte_count	[in] number of bytes in buffer[]

Returns: An ON_ContentHash with size and SHA-1 hash calculated from the parameters, hash time = now, and content last modified time = 0.

◆ CreateFromFile() [1/3]

static ON_ContentHash ON_ContentHash::CreateFromFile	(	ON_SHA1_Hash	sha1_file_name_hash,
		FILE *	fp
	)

static

Parameters

sha1_file_name_hash	[in] A SHA-1 hash of the file name associated with fp. Use ON_SHA1_Has::FileSystemPathHash() to create the value. If the name is not known, pass ON_SHA1_Hash::ZeroDigest.
fp	[in] pointer to a file opened with ON:FileOpen(...,"rb")

Returns: An ON_ContentHash with size and SHA-1 hash and times set from the file, hash time = now, and content last modifed time set from the file system information returned by ON_FileStream::GetFileInformation().

◆ CreateFromFile() [2/3]

static ON_ContentHash ON_ContentHash::CreateFromFile ( const wchar_t * filename )

static

Parameters

filename [in] name of file.

Returns: An ON_ContentHash with size and SHA-1 hash and times set from the file, hash time = now, and content last modifed time set from the file system information returned by ON_FileStream::GetFileInformation().

◆ CreateFromFile() [3/3]

static ON_ContentHash ON_ContentHash::CreateFromFile ( const char * filename )

static

◆ DifferentContent()

static bool ON_ContentHash::DifferentContent	(	const ON_ContentHash &	a,
		const ON_ContentHash &	b
	)

static

Returns: true if a and b have differnt ByteCount() or SHA-1 content hash values.

◆ Dump()

void ON_ContentHash::Dump ( class ON_TextLog & text_log ) const

◆ EqualContent()

static bool ON_ContentHash::EqualContent	(	const ON_ContentHash &	a,
		const ON_ContentHash &	b
	)

static

Returns: true if a and b have identical ByteCount() and SHA-1 content hash values.

◆ EqualFileNameSizeAndTime()

bool ON_ContentHash::EqualFileNameSizeAndTime ( const wchar_t * filename ) const

Parameters

filename [in]

Returns: True if the file exists, has size > 0, has the same name, same size, and same last modified time than this content hash. False otherwise.

Faster than the ON_ContentHash::EqualContent() and reliable if this content hash was set on the same file system. Unreliable if the file system does not correctly set last modified times or the file was modified less than 2 seconds before the call.

◆ HashCalculationTime()

ON__UINT64 ON_ContentHash::HashCalculationTime ( ) const

Returns: Time the hash SHA-1 hash was cacluated in seconds since January 1, 1970 UCT.

◆ IsNotSet()

bool ON_ContentHash::IsNotSet ( ) const

Returns: True if the SHA-1 hash is not set.

◆ IsSameBufferContent()

bool ON_ContentHash::IsSameBufferContent	(	const void *	buffer,
		size_t	byte_count
	)		const

Test a buffer to see if it has a matching size and SHA-1 hash.

Parameters

buffer	[in]
byte_count	[in] number of bytes in buffer[]

Returns: True if the buffer has a matching byte_count and SHA-1 hash.

◆ IsSameFileContent() [1/3]

bool ON_ContentHash::IsSameFileContent ( FILE * fp ) const

Test a file to see if it has a matching size and SHA-1 hash. Paramters: fp - [in] pointer to file opened with ON::OpenFile(...,"rb") bSkipTimeCheck - [in] if true, the time of last modification is not checked.

Returns: True if the file existes, can be read, and has a matching byte_count and SHA-1 hash.

◆ IsSameFileContent() [2/3]

bool ON_ContentHash::IsSameFileContent ( const wchar_t * filename ) const

Test a file to see if it has a matching size and SHA-1 content hash. Paramters: filename - [in]

Returns: True if the file exists, can be read, and has a matching byte_count and SHA-1 content hash.

◆ IsSameFileContent() [3/3]

bool ON_ContentHash::IsSameFileContent ( const char * filename ) const

◆ IsSet()

bool ON_ContentHash::IsSet ( ) const

Returns: True if the SHA-1 hash has been set.

◆ NameHash()

ON_SHA1_Hash ON_ContentHash::NameHash ( ) const

Returns: SHA-1 hash of the name (typically a full path file name).

◆ operator=()

ON_ContentHash& ON_ContentHash::operator= ( const ON_ContentHash & )

default

◆ Read()

bool ON_ContentHash::Read ( class ON_BinaryArchive & archive )

◆ Write()

bool ON_ContentHash::Write ( class ON_BinaryArchive & archive ) const

Member Data Documentation

◆ Unset

const ON_ContentHash ON_ContentHash::Unset

static

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Member Enumeration Documentation

◆ CompareResult

Constructor & Destructor Documentation

◆ ON_ContentHash() [1/2]

◆ ~ON_ContentHash()

◆ ON_ContentHash() [2/2]

Member Function Documentation

◆ ByteCount()

◆ Compare() [1/3]

◆ Compare() [2/3]

◆ Compare() [3/3]

◆ CompareContent()

◆ CompareResultFromUnsigned()

◆ ContentHash()

◆ ContentLastModifiedTime()

◆ Create()

◆ CreateFromBuffer()

◆ CreateFromFile() [1/3]

◆ CreateFromFile() [2/3]

◆ CreateFromFile() [3/3]

◆ DifferentContent()

◆ Dump()

◆ EqualContent()

◆ EqualFileNameSizeAndTime()

◆ HashCalculationTime()

◆ IsNotSet()

◆ IsSameBufferContent()

◆ IsSameFileContent() [1/3]

◆ IsSameFileContent() [2/3]

◆ IsSameFileContent() [3/3]

◆ IsSet()

◆ NameHash()

◆ operator=()

◆ Read()

◆ Write()

Member Data Documentation

◆ Unset