md_api.h File Reference

#include <string>
#include <list>
#include <vector>
#include <sys/types.h>
#include <dirent.h>

Go to the source code of this file.

Classes
class	AttributeList
class	EntryList
class	UploadHandle
Defines
#define	_FILE_OFFSET_BITS   64
#define	MD_ERR_OK   0
#define	MD_ERR_NOENT   1
#define	MD_ERR_ILCMD   3
#define	MD_ERR_PERM   4
#define	MD_ERR_INTERNAL   9
#define	MD_ERR_NOKEY   7
Functions
int	translateError (int amga)
int	addAttr (const std::string &dir, const std::string &key, const std::string &type="varchar(256)")
	Adds a new attribute of a directory(collection).
int	getAttr (const std::string &file, const std::string &key, std::string &attr)
	A simple interface to access the attributes of an entry.
int	getAttr (MDClient &client, const std::string &file, const std::string &key, std::string &attr)
	getAttr with external handling of the connection
int	amgaStat (MDClient &client, const std::string &file, struct stat *stbuf)
	Sets one ore more attributes of a file.
int	amgaReadlink (MDClient &client, const char *path, char *buf, size_t size)
int	setAttr (const std::string &file, const std::vector< std::string > &keys, const std::vector< std::string > &values)
	Sets one ore more attributes of a file.
int	setAttr (MDClient &client, const std::string &file, const std::vector< std::string > &keys, const std::vector< std::string > &values)
	Version of setAttr with external client management.
int	listAttr (MDClient &client, const std::string &file, std::list< std::string > &attrList, std::list< std::string > &types)
	Version of listAttr with external client management.
int	listAttr (const std::string &file, std::list< std::string > &attrList, std::list< std::string > &types)
	Lists the attributes of a file.
int	removeAttr (const std::string &file, const std::string &key)
	Version of removeAttr with external management of client.
int	clearAttr (const std::string &file, const std::string &key)
	Resets the value of a given attribute of a file.
int	createDir (const std::string &dir)
	Function to create a directory (collection).
int	getAttr (const std::string &pattern, const std::list< std::string > &keys, AttributeList &attributes)
	More complex interface to getting atributes using an iterator.
int	findEntries (const std::string &pattern, const std::string &query, EntryList &entries)
	Finds entries in the catalogue matching a query.
int	link (const std::string &file, const std::string &URL)
	Creates a link to another entry or an entry pointing to an external location.
int	upload (const std::string &dir, const std::vector< std::string > &keys, UploadHandle &handle)
	Bulk upload of entries and their attributes.
DIR *	amgaOpendir (MDClient &client, const char *name)
dirent *	amgaReaddir (MDClient &client, DIR *dir)
int	amgaClosedir (MDClient &client, DIR *dir)

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Define Documentation

#define _FILE_OFFSET_BITS   64

Definition at line 24 of file md_api.h.

#define MD_ERR_ILCMD   3

Definition at line 35 of file md_api.h.

#define MD_ERR_INTERNAL   9

Definition at line 37 of file md_api.h.

#define MD_ERR_NOENT   1

Definition at line 34 of file md_api.h.

#define MD_ERR_NOKEY   7

Definition at line 38 of file md_api.h.

#define MD_ERR_OK   0

Definition at line 33 of file md_api.h.

#define MD_ERR_PERM   4

Definition at line 36 of file md_api.h.

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Function Documentation

int addAttr	(	const std::string &	dir,
		const std::string &	key,
		const std::string &	type
	)

Adds a new attribute of a directory(collection).

Adds a new attribute to the list of attributes to a directory or collection, giving its name and type. If the type is not given, then currently "text" is use, which is an arbitrarily long ASCII text. Type is only used as the storage type in the backend. The communication between client and server is allways pure ASCII.

Parameters:

	dir	The directory(collection) affected
	key	The name of the attribute
	type	The storage type of the attribute in the backend

Returns:

Error code (Including errors returned by the addattr metadata interface command):

• 0 OK
• -1 Client-Server connection failed
• MD_ERR_NOENT: Directory does not exist
• MD_ERR_PERM: Permission denied. You need write permission on the directory

Definition at line 606 of file md_api.cc.

References MDClient::execute().

int amgaClosedir	(	MDClient &	client,
		DIR *	dir
	)

Definition at line 918 of file md_api.cc.

References MDClient::eot(), and MDClient::fetchRow().

DIR* amgaOpendir	(	MDClient &	client,
		const char *	name
	)

Definition at line 850 of file md_api.cc.

References MDClient::execute(), and translateError().

struct dirent* amgaReaddir	(	MDClient &	client,
		DIR *	dir
	)

Definition at line 874 of file md_api.cc.

References MDClient::eot(), MDClient::fetchRow(), and translateError().

int amgaReadlink	(	MDClient &	client,
		const char *	path,
		char *	buf,
		size_t	size
	)

Definition at line 262 of file md_api.cc.

References MDClient::eot(), MDClient::execute(), MDClient::fetchRow(), and translateError().

int amgaStat	(	MDClient &	client,
		const std::string &	file,
		struct stat *	stbuf
	)

Sets one ore more attributes of a file.

The attributes are given by the caller as a list of strings, which needs to match the length of the values to be assigned. The keys need to be defined with addAttr() first.

Parameters:

	file	The file name of the entry
	keys	A list of keys
	values	The list of values which are assigend to the keys

Returns:

Error code (including errors returned by the setattr metadata interface command):

• 0 OK
• -1 Client-Server connection problems
• MD_ERR_NOENT: No such file or directory
• MD_ERR_ILCMD: Illegal command: keys and values size mismatch
• MD_ERR_PERM: Permission denied. You need write permission on the entry

Definition at line 141 of file md_api.cc.

References MDClient::eot(), MDClient::execute(), MDClient::fetchRow(), and translateError().

int clearAttr	(	const std::string &	file,
		const std::string &	key
	)

Resets the value of a given attribute of a file.

Sets the attribute of a file to NULL. getAttr() will return this value as an empty string.

Parameters:

	file	Name of the entry
	key	Name of the attribute

Returns:

Error code (Including errors returned by the clearattr metadata interface command):

• 0 OK
• -1 Client-Server connection failed
• MD_ERR_NOENT: Unknown directory
• MD_ERR_PERM: Permission denied. You need write permission on the file

Definition at line 444 of file md_api.cc.

References MDClient::execute().

int createDir

(

const std::string &

dir

)

Function to create a directory (collection).

Creates a new directory. You will need to have write permissions in the parent directory and the directory should not already exist.

Parameters:

dir

The desired name of the directory

Returns:

Error code (Including errors returned by the createdir metadata interface command):

• 0 OK
• -1 Client-Server connection failed
• MD_ERR_NOENT: Parent directory does not exist
• MD_ERR_PERM: Permission denied. You need write permission on the parent directory

Definition at line 579 of file md_api.cc.

References MDClient::execute().

int findEntries	(	const std::string &	pattern,
		const std::string &	query,
		EntryList &	entries
	)

Finds entries in the catalogue matching a query.

Finds all files in the catalogue matching a given filename pattern and SQL-like query. The matching entries are returned via an EntryList object.

Parameters:

	pattern	The pattern matching possible filenames(entries)
	query	The SQL-Like query which winds up in the WHERE clause of the SQL-SELECT statement
	entries	The returned EntryList object holding the streamed connection to the server (call getEntry on it to get hold of the entries).

Returns:

Error code (including errors returned by the find metadata interface command):

• 0 OK
• -1 Client-Server connection failed
• MD_ERR_NOENT: No file matches pattern

Definition at line 661 of file md_api.cc.

References EntryList::connect(), and MDClient::execute().

int getAttr	(	const std::string &	pattern,
		const std::list< std::string > &	keys,
		AttributeList &	attributes
	)

More complex interface to getting atributes using an iterator.

Returns an AttributeList object holding a streamed connection to the metadata server which allows to iteratively get the filenames and values of several attributes of multiple files matching a given pattern.

Parameters:

	pattern	The pattern the filenames need to match
	keys	The names of the attributes as a list of strings
	attributes	The AttributeList structure returned by the call

Returns:

Error code (Including errors returned by the getattr metadata interface command):

• 0 OK
• -1 Client-Server connection failed
• MD_ERR_NOENT: Unknown directory
• MD_ERR_PERM: Permission denied. You need read permission on the file

Definition at line 470 of file md_api.cc.

References AttributeList::connect(), and MDClient::execute().

int getAttr	(	MDClient &	client,
		const std::string &	file,
		const std::string &	key,
		std::string &	attr
	)

getAttr with external handling of the connection

Definition at line 93 of file md_api.cc.

References MDClient::execute(), and MDClient::fetchRow().

int getAttr	(	const std::string &	file,
		const std::string &	key,
		std::string &	value
	)

A simple interface to access the attributes of an entry.

This command sends the getattr metadata interface command to a metadata server and returns the value of a single key for a given files.

Parameters:

	file	Name of the file
	key	The key name
	value	The value of the file which is filled

Returns:

Error value (including errors of the getattr interface command):

• 0 in case of everything went OK,
• -1 if something went wrong with the client-server connection
• MD_ERR_NOENT: No such file or directory
• MD_ERR_PERM: Permission denied. You need read permission on the file

Definition at line 83 of file md_api.cc.

References getAttr().

int link	(	const std::string &	file,
		const std::string &	URL
	)

Creates a link to another entry or an entry pointing to an external location.

Creates a link to another entry in the catalogue or lets the entry point to an external location. Note that metadata is associated with logical filenames and thus the implementation will not follow this link where metadata related queries of updates are concerned. Local links must have the protocol file: while everything else is considered to be a pointer to an external catalogue.

Parameters:

	file	The entry affected
	URL	The link location

Returns:

Error code (Including errors returned by the addattr metadata interface command):

• 0 OK
• -1 Client-Server connection failed
• MD_ERR_NOENT: Parent directory does not exist
• MD_ERR_PERM: Permission denied. You need write permission on the directory

Definition at line 635 of file md_api.cc.

References MDClient::execute().

int listAttr	(	const std::string &	file,
		std::list< std::string > &	attrList,
		std::list< std::string > &	types
	)

Lists the attributes of a file.

For a given file this functioin returns a list of attributes of a directory and their types. Note that also attributes which are undefined (assigned to NULL) for the entry are listed.

Parameters:

	file	Entry name
	attrList	Returns the attributes' names as a list of strings
	types	Returns the list of associated types as strings

Returns:

Error value (including errors returned by the listattr metadata interface command):

• 0 OK
• -1 Client-Server connection failed
• MD_ERR_NOENT: No such file or directory
• MD_ERR_PERM: Permission denied. You need read permission for the entry.

Definition at line 365 of file md_api.cc.

References listAttr().

int listAttr	(	MDClient &	client,
		const std::string &	file,
		std::list< std::string > &	attrList,
		std::list< std::string > &	types
	)

Version of listAttr with external client management.

Definition at line 375 of file md_api.cc.

References MDClient::eot(), MDClient::execute(), and MDClient::fetchRow().

int removeAttr	(	const std::string &	file,
		const std::string &	key
	)

Version of removeAttr with external management of client.

Definition at line 424 of file md_api.cc.

References removeAttr().

int setAttr	(	MDClient &	client,
		const std::string &	file,
		const std::vector< std::string > &	keys,
		const std::vector< std::string > &	values
	)

Version of setAttr with external client management.

Definition at line 332 of file md_api.cc.

References MDClient::execute().

int setAttr	(	const std::string &	file,
		const std::vector< std::string > &	keys,
		const std::vector< std::string > &	values
	)

Sets one ore more attributes of a file.

The attributes are given by the caller as a list of strings, which needs to match the length of the values to be assigned. The keys need to be defined with addAttr() first.

Parameters:

	file	The file name of the entry
	keys	A list of keys
	values	The list of values which are assigend to the keys

Returns:

Error code (including errors returned by the setattr metadata interface command):

• 0 OK
• -1 Client-Server connection problems
• MD_ERR_NOENT: No such file or directory
• MD_ERR_ILCMD: Illegal command: keys and values size mismatch
• MD_ERR_PERM: Permission denied. You need write permission on the entry

Definition at line 321 of file md_api.cc.

References setAttr().

int translateError

(

int

amga

)

Definition at line 51 of file md_api.cc.

References MD_ERR_ILCMD, MD_ERR_INTERNAL, MD_ERR_NOENT, MD_ERR_NOKEY, MD_ERR_OK, and MD_ERR_PERM.

Referenced by amgaOpendir(), amgaReaddir(), amgaReadlink(), and amgaStat().

int upload	(	const std::string &	dir,
		const std::vector< std::string > &	keys,
		UploadHandle &	handle
	)

Bulk upload of entries and their attributes.

The attributes' names are given by the caller as a list of strings. They need to be defined with addAttr() first. Sets up UploadHandle so that it can be used to upload the entries, and finally commit the changes (or abort the transaction).

Parameters:

	dir	The name of the collection affected
	keys	A list of keys
	handle	Reference to the UploadHandle which is used afterwards to upload the entries.

Returns:

Error code (including errors returned by the upload metadata interface command):

• 0 OK
• -1 Client-Server connection problems
• MD_ERR_NOENT: No such file or directory
• MD_ERR_ILCMD: Illegal command: keys and values size mismatch
• MD_ERR_PERM: Permission denied. You need write permission on the entry

Definition at line 825 of file md_api.cc.

References UploadHandle::connect(), and MDClient::execNoWait().

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