Oracle Multimedia provides the ORDSource object type, which supports access to a variety of sources of multimedia data. It supports access to data sources locally in a BLOB within the database, externally from a BFILE on a local file system, externally from a URL on an HTTP server, or externally from a user-defined source on another server.
The ORDSource object type is defined in the ordsrcsp.sql file. After installation, this file is available in the Oracle home directory at:
<ORACLE_HOME>/ord/im/admin (on Linux and UNIX)
<ORACLE_HOME>\ord\im\admin (on Windows)
This chapter contains these sections:
Note:
This object is used only by other Oracle Multimedia objects. The information in this chapter is included for reference only. Oracle does not recommend that you use this type.Methods invoked at the ORDSource level that are handed off to the source plug-in for processing have ctx (RAW) as the first argument. Before calling any of these methods for the first time, the client must allocate the ctx structure, initialize it to NULL, and invoke the open( ) method. At this point, the source plug-in can initialize context for this client. When processing is complete, the client must invoke the close( ) method.
Methods invoked from a source plug-in call have the first argument as obj (ORDSource) and the second argument as ctx (RAW).
Note:
In the current release, none of the plug-ins provided by Oracle and not all source or format plug-ins use the ctx argument, but if you code as previously described, your application should work with current or future source or format plug-ins.The ORDSource object does not attempt to maintain consistency, for example, with local and upDateTime attributes. It is up to you to maintain consistency. ORDAudio, ORDDoc, ORDImage, and ORDVideo objects all maintain consistency of their included ORDSource object.
The ORDSource object type supports access to a variety of sources of multimedia data. The attributes for this object type are defined as follows in the ordsrcsp.sql file:
------------------- -- TYPE ATTRIBUTES ------------------- localData BLOB, srcType VARCHAR2(4000), srcLocation VARCHAR2(4000), srcName VARCHAR2(4000), updateTime DATE, local NUMBER,
where:
localData: the locally stored multimedia data stored as a BLOB within the object. Depending on the block size, up to 8 terabytes (TB) to 128 TB of data can be stored as a BLOB within Oracle Database, and is protected by the Oracle security and transaction environment.
srcType: the data source type. (See Table 2-1 for the list of valid values.)
srcLocation: the place where data can be found based on the srcType value. (See Table 2-2 for the list of valid values.)
srcName: the data object name. (See Table 2-3 for the list of valid values.)
updateTime: the time at which the data was last updated.
local: a flag that indicates whether the data is local. The valid values are:
1: the data is in the BLOB.
0: the data is in external sources.
NULL: the data is local. This value may indicate a default state when you first insert an empty row.
See Also:
Oracle Database SecureFiles and Large Objects Developer's Guide for more information about using BLOBs
This section presents ORDSource reference information about these ORDSource methods, which are provided for source data manipulation:
See Also:
Oracle Database Concepts for more information about object types and methods
Resets the local attribute value from 1, meaning the source of the data is stored locally in a BLOB in the database, to 0, meaning the source of the data is stored externally.
This method sets the local attribute to 0, meaning the data is stored externally or outside the database.
The source plug-in context information. (See Section 8.1.)
Calling this method uses the ORDPLUGINS.ORDX_<srcType>_SOURCE plug-in package.
The return INTEGER is 0 (zero) for success and greater than 0 (for example, 1) for failure. The exact number and the meaning for that number is plug-in defined. For example, for the file plug-in, 1 might mean "File not found," 2 might mean "No such directory," and so on.
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the close( ) method and the value of the srcType attribute is NULL.
ORDSourceExceptions.METHOD_NOT_SUPPORTED
This exception is raised if you call the close( ) method and this method is not supported by the source plug-in being used.
See Appendix G for more information about these exceptions.
This method can be called after you export the data from the local source to an external data source and you no longer need this data in the local source.
export(ctx IN OUT RAW,
source_type IN VARCHAR2,
source_location IN VARCHAR2,
source_name IN VARCHAR2);
Copies data from the localData attribute within the database to an external data source.
Note:
The export( ) method provides native support only for a source.srcType value ofFILE. In this case, the data is exported to a file in a directory that is accessible to Oracle Database. User-defined sources can support the export( ) method to provide WRITE access to other types of data stores.The source plug-in context information. (See Section 8.1.)
The type of the external source data. This parameter is not case-sensitive. (See Table 2-1.)
The location to which the source data is to be exported. (See Table 2-2.)
The name of the object to which the source data is to be exported. (See Table 2-3.)
This method exports data from the localData attribute to the external data source specified by the input parameters.
Calling this method uses the ORDPLUGINS.ORDX_<srcType>_SOURCE plug-in package.
After exporting data, all attributes remain unchanged except the srcType, srcLocation, and srcName attributes, which are updated with input parameter values. After calling the export( ) method, you can call the clearLocal( ) method to indicate that the data is stored outside the database, and then call the deleteLocalContent( ) method to delete the content of the local data in the localData attribute.
When the source_type parameter has a value of FILE, the source_location parameter specifies the name of an Oracle directory object, and the source_name parameter specifies the name of the file in which the data is to be contained.
The export( ) method writes only to a database directory object that the user has privilege to access. That is, you can access a directory object that you have created using the SQL statement CREATE DIRECTORY, or one to which you have been granted READ and WRITE access.
For example, the following SQL*Plus commands create a directory object and grant the user ron permission to read and write to any file within the directory c:\mydir\work:
CONNECT sys as sysdba
Enter password: password
CREATE OR REPLACE DIRECTORY FILE_DIR AS 'c:\mydir\work';
GRANT READ,WRITE ON DIRECTORY FILE_DIR TO ron;
Now, the user ron can export an image to the testimg.jpg file in this directory using the export( ) method of the ORDImage object:
img.export('FILE', 'FILE_DIR', testimg.jpg');
Invoking this method implicitly calls the setUpdateTime( ) method.
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the export( ) method and the value of the srcType attribute is NULL.
ORDSourceExceptions.METHOD_NOT_SUPPORTED
This exception is raised if you call the export( ) method and this method is not supported by the source plug-in being used.
See Appendix G for more information about these exceptions.
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the getBFile( ) method and the value of the srcType attribute is NULL.
ORDSourceExceptions.INVALID_SOURCE_TYPE
This exception is raised if you call the getBFile( ) method and the value of the srcType attribute is other than FILE.
See Appendix G for more information about these exceptions.
getContentInTempLob(ctx IN OUT RAW,
tempLob IN OUT NOCOPY BLOB,
mimeType OUT VARCHAR2,
format OUT VARCHAR2,
duration IN PLS_INTEGER := 10,
cache IN BOOLEAN := TRUE);
Transfers data from the current data source into a temporary LOB, which is to be allocated and initialized as a part of this call.
The source plug-in context information. (See Section 8.1.)
An uninitialized BLOB locator, which is to be allocated in this call.
An output parameter to receive the MIME type of the data, for example, audio/basic.
An output parameter to receive the format of the data, for example, AUFF.
The life of the temporary LOB to be allocated. The life of the temporary LOB can be for the duration of the call, the transaction, or for the session. The default is DBMS_LOB.SESSION. Valid values for each duration state are:
DBMS_LOB.CALL
DBMS_LOB.TRANSACTION
DBMS_LOB.SESSION
A Boolean value that indicates whether to keep the data cached. The value is either TRUE or FALSE. The default is TRUE.
NO_DATA_FOUND
This exception is raised if you call the getContentInLob( ) method when working with temporary LOBs for looping read operations that reach the end of the LOB, and there are no more bytes to be read from the LOB. (There is no ORD<object-type>Exceptions prefix to this exception because it is a predefined PL/SQL exception.)
See Appendix G for more information about these exceptions.
Returns the length of the data content stored in the source. For a file source and for data in the localData attribute, the length is returned as a number of bytes. The unit type of the returned value is defined by the plug-in that implements this method.
The source plug-in context information. (See Section 8.1.)
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the getContentLength( ) method and the value of the srcType attribute is NULL.
See Appendix G for more information about these exceptions.
Returns the source address for data located in an external data source. This method is implemented only for user-defined sources.
The source plug-in context information. (See Section 8.1.)
User input needed by some sources to obtain the desired source address.
Use this method to return the address of an external data source when the source must format this information in some unique way. For example, call the
getSourceAddress( ) method to obtain the address for RealNetworks server sources or URLs containing data sources located on Oracle Fusion Middleware.
Calling this method uses the ORDPLUGINS.ORDX_<srcType>_SOURCE plug-in package.
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the getSourceAddress( ) method and the value of the srcType attribute is NULL.
See Appendix G for more information about these exceptions.
Returns a URL formatted string containing complete information about the external data source.
This method returns a VARCHAR2 string formatted as: <srcType>://<srcLocation>/<srcName>, where srcType, srcLocation, and srcName are the ORDSource attribute values.
This method returns the current value of the srcLocation attribute, for example BFILEDIR.
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the getSourceLocation( ) method and the value of the srcType attribute is NULL.
ORDSourceExceptions.INCOMPLETE_SOURCE_LOCATION
This exception is raised if you call the getSourceLocation( ) method and the value of the srcLocation attribute is NULL.
See Appendix G for more information about these exceptions.
This method returns the current value of the srcName attribute, for example
testaud.dat.
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the getSourceName( ) method and the value of the srcType attribute is NULL.
ORDSourceExceptions.INCOMPLETE_SOURCE_NAME
This exception is raised if you call the getSourceName( ) method and the value of the srcName attribute is NULL.
See Appendix G for more information about these exceptions.
Returns the time stamp of when the object was last changed, or what the user explicitly set by calling the setUpdateTime( ) method. (This method returns the value of the updateTime attribute.)
Transfers data from an external data source (specified by first calling setSourceInformation( )) to the localData attribute within the database.
The source plug-in context information.This information is passed along uninterpreted to the source plug-in handling the import( ) call. (See Section 8.1.)
The output parameter to receive the MIME type of the data, if any, for example, audio/basic.
The output parameter to receive the format of the data, if any, for example, AUFF.
Before calling this method, call setSourceInformation( ) method to set the srcType, srcLocation, and srcName attribute values to describe where the data source is located.
Calling this method uses the ORDPLUGINS.ORDX_<srcType>_SOURCE plug-in package.
After importing data from an external data source to a local source (within Oracle Database), the source information remains unchanged (that is, pointing to the source from where the data was imported).
If the value of the srcType attribute is FILE, the srcLocation attribute contains the name of a database directory object which contains the file to be imported, and the srcName attribute contains the name of the file to be imported. You must ensure that the directory for the external source location exists or is created before you use this method.
The import( ) method reads only from a database directory object that the user has privilege to access. That is, you can access a directory object that you have created using the SQL statement CREATE DIRECTORY, or one to which you have been granted READ access.
For example, the following SQL*Plus commands create a directory object and grant the user ron permission to read any file within the directory c:\mydir\work:
CONNECT sys as sysdba Enter password: password CREATE OR REPLACE DIRECTORY FILE_DIR AS 'c:\mydir\work'; GRANT READ ON DIRECTORY FILE_DIR TO ron;
If the value of the srcType attribute is HTTP, the srcLocation attribute contains the base URL needed to find the source directory that contains the object to be imported, and the srcName attribute contains the name of the object to be imported.
This method uses the PL/SQL UTL_HTTP package to import media data from an HTTP data source. You can use environment variables to specify the proxy behavior of the UTL_HTTP package. For example, on Linux and UNIX, setting the environment variable http_proxy to a URL specifies that the UTL_HTTP package must use that URL as the proxy server for HTTP requests. Setting the no_proxy environment variable to a domain name specifies that the HTTP proxy server not be used for URLs in the specified domain.
See Also:
Oracle Database PL/SQL Packages and Types Reference for more information about the UTL_HTTP package
If the value of the source.srcType attribute is a user-defined name, the source.srcLocation attribute contains an identifier string required to access the user-defined object to be imported, and the source.srcName attribute contains the name of the object to be imported.
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the import( ) method and the value of the srcType attribute is NULL.
ORDSourceExceptions.METHOD_NOT_SUPPORTED
This exception is raised if you call the import( ) method and this method is not supported by the source plug-in being used.
ORDSourceExceptions.NULL_SOURCE
This exception is raised if you call the import( ) method and the value of the localData attribute is NULL.
See Appendix G for more information about these exceptions.
importFrom(ctx IN OUT RAW,
mimeType OUT VARCHAR2,
format OUT VARCHAR2
source_type IN VARCHAR2,
source_location IN VARCHAR2,
source_name IN VARCHAR2);
Transfers data from the specified external data source (type, location, name) to the localData attribute within the database, and resets the source attributes and the timestamp.
The source plug-in context information. This information is passed along uninterpreted to the source plug-in handling the importFrom( ) call. (See Section 8.1.)
The output parameter to receive the MIME type of the data, if any, for example, audio/basic.
The output parameter to receive the format of the data, if any, for example, AUFF.
The type of the source data to be imported. This also sets the srcType attribute. (See Table 2-1.)
The location from which the source data is to be imported. This also sets the srcLocation attribute. (See Table 2-2.)
The name of the source data to be imported. This also sets the srcName attribute. (See Table 2-3.)
This method describes where the data source is located by specifying values for the type, location, and name parameters, which set the srcType, srcLocation, and srcName attribute values, respectively, after the importFrom( ) operation succeeds. This method is a combination of a setSourceInformation( ) method followed by an import( ) method.
Calling this method uses the ORDPLUGINS.ORDX_<srcType>_SOURCE plug-in package.
If the value of the source_type parameter is FILE, the source_location parameter contains the name of a database directory object that contains the file to be imported, and the source_name parameter contains the name of the file to be imported. You must ensure that the directory indicated by the source_location parameter exists or is created before you use this method.
The importFrom( ) method reads only from a database directory object that the user has privilege to access. That is, you can access a directory object that you have created using the SQL statement CREATE DIRECTORY, or one to which you have been granted READ access.
For example, the following SQL*Plus commands create a directory object and grant the user ron permission to read any file within the directory c:\mydir\work:
CONNECT sys as sysdba Enter password: password CREATE OR REPLACE DIRECTORY FILE_DIR AS 'c:\mydir\work'; GRANT READ ON DIRECTORY FILE_DIR TO ron;
If the value of the source_type parameter is HTTP, the source_location parameter contains the base URL needed to find the source directory that contains the object to be imported, and the source_name parameter contains the name of the object to be imported.
This method uses the PL/SQL UTL_HTTP package to import media data from an HTTP data source. You can use environment variables to specify the proxy behavior of the UTL_HTTP package. For example, on Linux and UNIX, setting the environment variable http_proxy to a URL specifies that the UTL_HTTP package must use that URL as the proxy server for HTTP requests. Setting the no_proxy environment variable to a domain name specifies that the HTTP proxy server not be used for URLs in the specified domain.
See Also:
Oracle Database PL/SQL Packages and Types Reference for more information about the UTL_HTTP package
If the value of the source_type parameter is a user-defined name, the source_location parameter contains an identifier string required to access the user-defined object to be imported, and the source_name parameter contains the name of the object to be imported.
ORDSourceExceptions.METHOD_NOT_SUPPORTED
This exception is raised if you call the importFrom( ) method and this method is not supported by the source plug-in being used.
ORDSourceExceptions.NULL_SOURCE
This exception is raised if you call the importFrom( ) method and the value of the localData attribute is NULL.
See Appendix G for more information about these exceptions.
Returns TRUE if the data is stored as a BLOB locally in the localData attribute or FALSE if the data is stored externally.
If the local attribute is set to 1 or NULL, this method returns TRUE; otherwise this method returns FALSE.
Opens a data source. It is recommended that this method be called before invoking any other methods that accept the ctx parameter.
The user-defined input parameter.
The source plug-in context information. (See Section 8.1.)
Calling this method uses the ORDPLUGINS.ORDX_<srcType>_SOURCE plug-in package.
The return INTEGER is 0 (zero) for success and greater than 0 (for example, 1) for failure. The exact number and the meaning for that number is plug-in defined. For example, for the file plug-in, 1 might mean "File not found," 2 might mean "No such directory," and so on.
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the open( ) method and the value of the srcType attribute is NULL.
ORDSourceExceptions.METHOD_NOT_SUPPORTED
This exception is raised if you call the open( ) method and this method is not supported by the source plug-in being used.
See Appendix G for more information about these exceptions.
processCommand(ctx IN OUT RAW,
command IN VARCHAR2,
arglist IN VARCHAR2,
result OUT RAW)
RETURN RAW;
Lets you send commands and related arguments to the source plug-in. This method is supported only for user-defined sources.
The source plug-in context information. (See Section 8.1.)
Any command recognized by the source plug-in.
The arguments for the command.
The result of calling this method returned by the plug-in.
Use this method to send any commands and their respective arguments to the plug-in. Commands are not interpreted; they are taken and passed through to be processed.
Calling this method uses the ORDPLUGINS.ORDX_<srcType>_SOURCE plug-in package.
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the processCommand( ) method and the value of the srcType attribute is NULL.
ORDSourceExceptions.METHOD_NOT_SUPPORTED
This exception is raised if you call the processCommand( ) method and this method is not supported by the source plug-in being used.
See Appendix G for more information about these exceptions.
Lets you read a buffer of numBytes from a source beginning at a start position (startPos).
The source plug-in context information. (See Section 8.1.)
The start position in the data source.
The number of bytes to be read from the data source.
The buffer to where the data is to be read.
This method is not supported for HTTP sources.
To successfully read HTTP source types, the entire URL source must be requested to be read. To implement a read method for an HTTP source type, you must provide your own implementation for this method in the modified source plug-in for the HTTP source type.
Calling this method uses the ORDPLUGINS.ORDX_<srcType>_SOURCE plug-in package.
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the read( ) method and the value of the srcType attribute is NULL.
ORDSourceExceptions.METHOD_NOT_SUPPORTED
This exception is raised if you call the read( ) method and this method is not supported by the source plug-in being used.
ORDSourceExceptions.NULL_SOURCE
This exception is raised if you call the read( ) method and the value of the local attribute is 1 or NULL, but the value of the localData attribute is NULL.
See Appendix G for more information about these exceptions.
Sets the local attribute to indicate that the BLOB data is stored in the localData attribute within the database.
This method sets the local attribute to 1, meaning the data is stored locally in the localData attribute.
setSourceInformation(source_type IN VARCHAR2,
source_location IN VARCHAR2,
source_name IN VARCHAR2);
Sets the provided subcomponent information for the srcType, srcLocation, and srcName attributes that describes the external data source.
Before you call the import( ) method, you must call the setSourceInformation( ) method to set the srcType, srcLocation, and srcName attribute information to describe where the data source is located. If you call the importFrom( ) or the export( ) method, then these attributes are set after the importFrom( ) or export( ) call succeeds.
You must ensure that the directory indicated by the source_location parameter exists or is created before you use this method.
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the setSourceInformation( ) method and the value of the source_type parameter is NULL.
See Appendix G for more information about this exception.
The source plug-in context information. (See Section 8.1.)
The trimmed new length.
Calling this method uses the ORDPLUGINS.ORDX_<srcType>_SOURCE plug-in package.
The return INTEGER is 0 (zero) for success and greater than 0 (for example, 1) for failure. The exact number and the meaning for that number is plug-in defined. For example, for the file plug-in, 1 might mean "File not found," 2 might mean "No such directory," and so on.
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the trim( ) method and the value of the srcType attribute is NULL.
ORDSourceExceptions.METHOD_NOT_SUPPORTED
This exception is raised if you call the trim( ) method and this method is not supported by the source plug-in being used.
See Appendix G for more information about these exceptions.
Lets you write a buffer of numBytes to a source beginning at a start position (startPos).
The source plug-in context information. (See Section 8.1.)
The start position in the source to where the buffer is to be copied.
The number of bytes to be written to the source.
The buffer of data to be written.
This method assumes that the source lets you write numBytes at a random byte location. For example, the FILE and HTTP source types cannot be written to and do not support this method.
Calling this method uses the ORDPLUGINS.ORDX_<srcType>_SOURCE plug-in package.
ORDSourceExceptions.INCOMPLETE_SOURCE_INFORMATION
This exception is raised if you call the write( ) method and the value of the srcType attribute is NULL.
ORDSourceExceptions.METHOD_NOT_SUPPORTED
This exception is raised if you call the write( ) method and this method is not supported by the source plug-in being used.
ORDSourceExceptions.NULL_SOURCE
This exception is raised if you call the read( ) method and the value of the local attribute is 1 or NULL, but the value of the localData attribute is NULL.
See Appendix G for more information about these exceptions.