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GNOME Data Access manual | ![]() |
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GdaBlob; enum GdaBlobMode; gint gda_blob_open (GdaBlob *blob, GdaBlobMode mode); gint gda_blob_read (GdaBlob *blob, gpointer buf, gint size, gint *bytes_read); gint gda_blob_write (GdaBlob *blob, gpointer buf, gint size, gint *bytes_written); gint gda_blob_lseek (GdaBlob *blob, gint offset, gint whence); gint gda_blob_close (GdaBlob *blob); gint gda_blob_remove (GdaBlob *blob); gchar* gda_blob_get_sql_id (GdaBlob *blob);
typedef enum { GDA_BLOB_MODE_READ = 1, GDA_BLOB_MODE_WRITE = 1 << 1, GDA_BLOB_MODE_RDWR = 0x03 } GdaBlobMode;
gint gda_blob_open (GdaBlob *blob, GdaBlobMode mode);
Opens an existing BLOB. The BLOB must be initialized by gda_connection_create_blob or obtained from a GValue.
blob : |
an existing GdaBlob |
mode : |
see GdaBlobMode. |
Returns : | 0 if everything's ok. In case of error, -1 is returned and the provider should have added an error (a GdaConnectionEvent) to the connection. |
gint gda_blob_read (GdaBlob *blob, gpointer buf, gint size, gint *bytes_read);
Reads a chunk of bytes from the BLOB into a user-provided location.
blob : |
a GdaBlob which is opened with the flag GDA_BLOB_MODE_READ set. |
buf : |
buffer to read the data into. |
size : |
maximum number of bytes to read. |
bytes_read : |
on return it will point to the number of bytes actually read. |
Returns : | 0 if everything's ok. In case of error, -1 is returned and the provider should have added an error to the connection. |
gint gda_blob_write (GdaBlob *blob, gpointer buf, gint size, gint *bytes_written);
Writes a chunk of bytes from a user-provided location to the BLOB.
blob : |
a GdaBlob which is opened with the flag GDA_BLOB_MODE_WRITE set. |
buf : |
buffer to write the data from. |
size : |
maximum number of bytes to read. |
bytes_written : |
on return it will point to the number of bytes actually written. |
Returns : | 0 if everything's ok. In case of error, -1 is returned and the provider should have added an error to the connection. |
gint gda_blob_lseek (GdaBlob *blob, gint offset, gint whence);
Sets the blob read/write position.
blob : |
a opened GdaBlob. |
offset : |
offset added to the position specified by whence .
|
whence : |
SEEK_SET, SEEK_CUR or SEEK_END with the same meaning as in fseek(3). |
Returns : | the current position in the blob or < 0 in case of error. In case of error the provider should have added an error to the connection. |
gint gda_blob_close (GdaBlob *blob);
Closes the BLOB. After calling this function, blob
should no longer be used.
blob : |
a opened GdaBlob. |
Returns : | 0 if everything's ok. In case of error, -1 is returned and the provider should have added an error to the connection. |
gint gda_blob_remove (GdaBlob *blob);
Removes the BLOB from the database. After calling this function, blob
should no longer be used.
blob : |
a valid GdaBlob. |
Returns : | 0 if everything's ok. In case of error, -1 is returned and the provider should have added an error to the connection. |