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| author | Elena Pourmal <epourmal@hdfgroup.org> | 1998-07-08 22:28:21 (GMT) |
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| committer | Elena Pourmal <epourmal@hdfgroup.org> | 1998-07-08 22:28:21 (GMT) |
| commit | 49f626b81f028a09d5c287156120a5d405008335 (patch) | |
| tree | ee0178875371da97373cb5c08a2fa7a276f94ccd /doc/src/RM_H5A.html | |
| parent | 2f1f2ac4e44efef28ac7b7edaf4f9470b866c9fc (diff) | |
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[svn-r475] HDF5 Reference Manual files.
Main file is RM_H5Front.html. Created from the Alpha1 Ref. Manual, Alpha1
User's Guide Documents and the Alpha2 Source Code.
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| -rw-r--r-- | doc/src/RM_H5A.html | 506 |
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diff --git a/doc/src/RM_H5A.html b/doc/src/RM_H5A.html new file mode 100644 index 0000000..a6738e4 --- /dev/null +++ b/doc/src/RM_H5A.html @@ -0,0 +1,506 @@ +<html> +<head><title> +HDF5/H5A Draft API Specification +</title></head> + +<body> + +<center> +<h1>H5A: Attribute Interface</h1> +</center> + +<h2>Attribute API Functions</h2> + +These functions create and manipulate attributes +and information about attributes. + +<table border=0> +<tr><td valign=top> +<ul> + <li><a href="#Annot-Create">H5Acreate</a> + <li><a href="#Annot-Write">H5Awrite</a> + <li><a href="#Annot-Read">H5Aread</a> + <li><a href="#Annot-Close">H5Aclose</a> +</ul> +</td><td> </td><td valign=top> +<ul> + <li><a href="#Annot-GetName">H5Aget_name</a> + <li><a href="#Annot-OpenName">H5Aopen_name</a> + <li><a href="#Annot-OpenIdx">H5Aopen_idx</a> + <li><a href="#Annot-GetSpace">H5Aget_space</a> +</ul> +</td><td> </td><td valign=top> +<ul> + <li><a href="#Annot-GetType">H5Aget_type</a> + <li><a href="#Annot-NumAttrs">H5Anum_attrs</a> + <li><a href="#Annot-Iterate">H5Aiterate</a> + <li><a href="#Annot-Delete">H5Adelete</a> +</ul> +</td></tr> +</table> + + +<hr> +<dl> +<dt><strong>Name:</strong> <a name="Annot-Create">H5Acreate</a> +<dt><strong>Signature:</strong> + <dd><em>hid_t</em> <code>H5Acreate</code>(<em>hid_t</em> <code>loc_id</code>, + <em>const char *</em><code>name</code>, + <em>hid_t</em> <code>datatype</code>, + <em>hid_t</em> <code>dataspace</code>, + <em>hid_t</em> <code>create_plist</code> + ) +<dt><strong>Purpose:</strong> + <dd>Creates a dataset as an attribute of another dataset or group. +<dt><strong>Description:</strong> + <dd>SC: <code>H5Acreate</code> creates an attribute which is attached to the object + specified with 'location_id'. The name specified with 'name' for each + attribute for an object must be unique for that object. The 'type_id' + and 'space_id' are created with the H5T and H5S interfaces respectively. + Currently only simple dataspaces are allowed for attribute dataspaces. + The 'create_plist_id' property list is currently un-used, but will be + used int the future for optional properties of attributes. The attribute + identifier returned from this function must be released with H5Aclose or resource + leaks will develop. + <p> + The link created (see H5G API documentation for more information on + link types) is a hard link, so the attribute may be shared among datasets + and will not be removed from the file until the reference count for the + attribute is reduced to zero. + <p> + The location object may be either a group or a dataset, both of + which may have any sort of attribute. + <p> + UG: <code>H5Acreate</code> creates an attribute which is attached to the object + specified with <em>loc_id</em>. The name specified with <em>name</em> + for each attribute for an object must be unique for that object. The <em>type_id</em> + and <em>space_id</em> are created with the H5T and H5S interfaces + respectively. Currently only simple dataspaces are allowed for attribute + dataspaces. The <em>create_plist_id</em> property list is currently + unused, but will be used int the future for optional properties of + attributes. The attribute identifier returned from this function must be released + with H5Aclose or resource leaks will develop. Attempting to create an + attribute with the same name as an already existing attribute will fail, + leaving the pre-existing attribute in place. + <p> + <b>datatype, dataspace, create_plist in the UG are + type_id, space_id, and create_plist_id, respectively, in the SC</b> + <p> +<dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>loc_id</code> + <dd>IN: Object (dataset or group) to be attached to + <dt><em>const char *</em><code>name</code> + <dd>IN: Name of attribute to create + <dt><em>hid_t</em> <code>datatype</code> + <dd>IN: Identifier of datatype for attribute + <dt><em>hid_t</em> <code>dataspace</code> + <dd>IN: Identifier of dataspace for attribute + <dt><em>hid_t</em> <code>create_plist</code> + <dd>IN: Identifier of creation property list (currently not used) + </dl> +<dt><strong>Returns:</strong> + <dd>Returns an attribute identifier if successful; + otherwise FAIL (-1). +</dl> + + +<hr> +<dl> +<dt><strong>Name:</strong> <a name="Annot-OpenName">H5Aopen_name</a> +<dt><strong>Signature:</strong> + <dd><em>hid_t</em> <code>H5Aopen_name</code>(<em>hid_t</em> <code>loc_id</code>, + <em>const char *</em><code>name</code> + ) +<dt><strong>Purpose:</strong> + <dd> Opens an attribute for an object by looking up the attribute name. +<dt><strong>Description:</strong> + <dd> SC: <code>H5Aopen_name</code> opens an existing attribute for access. The attribute + name specified is used to look up the corresponding attribute for the + object. The attribute identifier returned from this function must be released with + H5Aclose or resource leaks will develop. + <p> + The location object may be either a group or a dataset, both of + which may have any sort of attribute. + <p> + UG: <code>H5Aopen_name</code> opens an attribute which is attached to the object + specified with loc_id. The name specified with name indicates the + attribute to access. The attribute identifier returned from this function must + be released with H5Aclose or resource leaks will develop. +<dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>loc_id</code> + <dd>IN: Object (dataset or group) to be attached to + <dt><em>const char *</em><code>name</code> + <dd>IN: Name of attribute to locate and open + </dl> +<dt><strong>Returns:</strong> + <dd>Returns attribute identifier if successful; + otherwise FAIL (-1). +</dl> + + +<hr> +<dl> +<dt><strong>Name:</strong> <a name="Annot-OpenIdx">H5Aopen_idx</a> +<dt><strong>Signature:</strong> + <dd><em>hid_t</em> <code>H5Aopen_idx</code>(<em>hid_t</em> <code>loc_id</code>, + <em>unsigned int</em> <code>idx</code> + ) +<dt><strong>Purpose:</strong> + <dd>Opens the <i>n</i>th attribute for an object. +<dt><strong>Description:</strong> + <dd>SC: <code>H5Aopen_idx</code> opens an existing attribute for access. The attribute + index specified is used to look up the corresponding attribute for the + object. The attribute identifier returned from this function must be released with + H5Aclose or resource leaks will develop. + <p> + The location object may be either a group or a dataset, both of + which may have any sort of attribute. + <p> + UG: <code>H5Aopen_idx</code> opens an attribute which is attached to the object + specified with loc_id. The attribute specified with idx indicates the + <i>idx</i>th attribute to access, starting with '0'. + The attribute identifier returned from this function must be released with + H5Aclose or resource leaks will develop. +<dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>loc_id</code> + <dd>IN: Object (dataset or group) to be attached to + <dt><em>unsigned int</em> <code>idx</code> + <dd>IN: Index (0-based) attribute to open + </dl> +<dt><strong>Returns:</strong> + <dd>Returns attribute identifier if successful; + otherwise FAIL (-1). +</dl> + + +<hr> +<dl> +<dt><strong>Name:</strong> <a name="Annot-Write">H5Awrite</a> +<dt><strong>Signature:</strong> + <dd><em>herr_t</em> <code>H5Awrite</code>(<em>hid_t</em> <code>attr_id</code>, + <em>hid_t</em> <code>mem_dt</code>, + <em>void *</em><code>buf</code> + ) +<dt><strong>Purpose:</strong> + <dd>Write out data to an attribute. +<dt><strong>Description:</strong> + <dd>SC: <code>H5Awrite</code> writes a complete attribute to disk. + <p> + UG: <code>H5Awrite</code> writes an attribute, specified with attr_id, + with mem_type_id specifying the datatype in memory. + The entire attribute is written from buf to the file. + This function returns non-negative on success, negative on failure. + <p> + <b>mem_dt in SC is mem_type_id in UG.</b> + <p> +<dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>attr_id</code> + <dd>IN: Attribute to write + <dt><em>hid_t</em> <code>mem_dt</code> + <dd>IN: Memory datatype of buffer + <dt><em>void *</em><code>buf</code> + <dd>IN: Buffer of data to write + </dl> +<dt><strong>Returns:</strong> + <dd>Returns SUCCEED (0) if successful; + otherwise FAIL (-1). +</dl> + + +<hr> +<dl> +<dt><strong>Name:</strong> <a name="Annot-Read">H5Aread</a> +<dt><strong>Signature:</strong> + <dd><em>herr_t</em> <code>H5Aread</code>(<em>hid_t</em> <code>attr_id</code>, + <em>hid_t</em> <code>mem_dt</code>, + <em>void *</em><code>buf</code> + ) +<dt><strong>Purpose:</strong> + <dd>Read in data from an attribute. +<dt><strong>Description:</strong> + <dd>SC: <code>H5Aread</code> reads a complete attribute from disk. + <p> + UG: <code>H5Aread</code> reads an attribute, specified with attr_id, + with mem_type_id specifying the datatype in memory. + The entire attribute is read into buf from the file. + This function returns non-negative on success, negative on failure. + <p> + <b>mem_dt in SC is mem_type_id in UG.</b> + <p> +<dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>attr_id</code> + <dd>IN: Attribute to read + <dt><em>hid_t</em> <code>mem_dt</code> + <dd>IN: Memory datatype of buffer + <dt><em>void *</em><code>buf</code> + <dd>IN: Buffer for data to read + </dl> +<dt><strong>Returns:</strong> + <dd>Returns SUCCEED (0) if successful; + otherwise FAIL (-1). +</dl> + + +<hr> +<dl> +<dt><strong>Name:</strong> <a name="Annot-GetSpace">H5Aget_space</a> +<dt><strong>Signature:</strong> + <dd><em>hid_t</em> <code>H5Aget_space</code>(<em>hid_t</em> <code>attr_id</code>) +<dt><strong>Purpose:</strong> + <dd>Gets a copy of the dataspace for an attribute. +<dt><strong>Description:</strong> + <dd><code>H5Aget_space</code> retrieves a copy of the dataspace for an attribute. + The dataspace identifier returned from this function must be released with H5Sclose + or resource leaks will develop. + <p> + <i>(Identical desc in UG and SC.)</i> + <p> +<dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>attr_id</code> + <dd>IN: Attribute to get dataspace of + </dl> +<dt><strong>Returns:</strong> + <dd>Returns dataspace identifier if successful; + otherwise FAIL (-1). +</dl> + + +<hr> +<dl> +<dt><strong>Name:</strong> <a name="Annot-GetType">H5Aget_type</a> +<dt><strong>Signature:</strong> + <dd><em>hid_t</em> <code>H5Aget_type</code>(<em>hid_t</em> <code>attr_id</code>) +<dt><strong>Purpose:</strong> + <dd>Gets a copy of the datatype for an attribute. +<dt><strong>Description:</strong> + <dd><code>H5Aget_type</code> retrieves a copy of the datatype for an attribute. + The datatype identifier returned from this function must be released with + H5Tclose or resource leaks will develop. + <p> + <i>(Identical desc in UG and SC.)</i> + <p> +<dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>attr_id</code> + <dd>IN: Attribute to get datatype of + </dl> +<dt><strong>Returns:</strong> + <dd>Returns a datatype identifier if successful; + otherwise FAIL (-1). +</dl> + + +<hr> +<dl> +<dt><strong>Name:</strong> <a name="Annot-GetName">H5Aget_name</a> +<dt><strong>Signature:</strong> + <dd><em>size_t</em> <code>H5Aget_name</code>(<em>hid_t</em> <code>attr_id</code>, + <em>char *</em><code>buf</code>, + <em>size_t</em> <code>buf_size</code> + ) +<dt><strong>Purpose:</strong> + <dd>Gets a copy of the name for an attribute. +<dt><strong>Description:</strong> + <dd><code>H5Aget_name</code> retrieves the name of an attribute for an attribute identifier. + Up to 'buf_size' characters are stored in 'buf' followed by a '\0' string + terminator. If the name of the attribute is longer than 'buf_size'-1, + the string terminator is stored in the last position of the buffer to + properly terminate the string. + <p> + <i>(Identical desc in UG and SC.)</i> + <p> +<dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>attr_id</code> + <dd>IN: Attribute to get name of + <dt><em>char *</em><code>buf</code> + <dd>IN: Buffer to store name in + <dt><em>size_t</em> <code>buf_size</code> + <dd>IN: The size of the buffer to store the string in + </dl> +<dt><strong>Returns:</strong> + <dd>Returns the length of the attribute's name, which may be + longer than <code>buf_size</code>, if successful. + Otherwise returns FAIL (-1). +</dl> + + +<hr> +<dl> +<dt><strong>Name:</strong> <a name="Annot-NumAttrs">H5Anum_attrs</a> +<dt><strong>Signature:</strong> + <dd><em>int</em> <code>H5Anum_attrs</code>(<em>hid_t</em> <code>loc_id</code>) +<dt><strong>Purpose:</strong> + <dd>Determines the number of attributes attached to an object. +<dt><strong>Description:</strong> + <dd><code>H5Anum_attrs</code> returns the number of attributes attached to the dataset or + group, <code>loc_id</code>. + <p> + <i>(Identical desc in UG and SC.)</i> + <p> +<dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>loc_id</code> + <dd>IN: The object, a dataset or group, to be queried + </dl> +<dt><strong>Returns:</strong> + <dd>Returns the number of attributes if successful; + otherwise FAIL (-1). +</dl> + + +<hr> +<dl> +<dt><strong>Name:</strong> <a name="Annot-Iterate">H5Aiterate</a> +<dt><strong>Signature:</strong> + <dd><em>int</em> <code>H5Aiterate</code>(<em>hid_t</em> <code>loc_id</code>, + <em>unsigned *</em> <code>attr_num</code>, + <em>H5A_operator_t</em> <code>op</code>, + <em>void *</em><code>op_data</code> + ) +<dt><strong>Purpose:</strong> + <dd>Calls a user's function for each attribute on an object. +<dt><strong>Description:</strong> + <dd>SC: H5Aiterate interates over the attributes of dataset or group + specified with 'loc_id'. For each attribute of the object, the + 'op_data' and some additional information (specified below) are passed + to the 'op' function. The iteration begins with the '*attr_number' + object in the group and the next attribute to be processed by the operator + is returned in '*attr_number'. + <p> + The operation receives the identifier for the group or dataset being iterated + over ('loc_id'), the name of the current attribute about the object + ('attr_name') and the pointer to the operator data passed in to H5Aiterate + ('op_data'). The return values from an operator are: + <ul> + <li>Zero causes the iterator to continue, returning zero when all + attributes have been processed. + <li>Positive causes the iterator to immediately return that positive + value, indicating short-circuit success. The iterator can be + restarted at the next attribute. + <li>Negative causes the iterator to immediately return that value, + indicating failure. The iterator can be restarted at the next + attribute. + </ul> + <dd>UG: <code>H5Aiterate</code> interates over the attributes of dataset or group + specified with loc_id. For each attribute of the object, + the operator_data and some additional information (specified below) + are passed to the operator function. The iteration begins with + the *attr_number object in the group and the next attribute to be + processed by the operator is returned in *attr_number. + <p> + The prototype for H5A_operator_t is: <br> + <code>typedef herr_t (*H5A_operator_t)(hid_t <em>loc_id</em>, + const char *<em>attr_name</em>, void *<em>operator_data</em>);</code> + <p> + The operation receives the identifier for the group or dataset being iterated over + (<em>loc_id</em>), the name of the current attribute about the object (<em>attr_name</em>) + and the pointer to the operator data passed in to H5Aiterate + (<em>operator_data</em>). The return values from an operator are: + <ul> + <li>Zero causes the iterator to continue, returning zero when all + attributes have been processed. + <li>Positive causes the iterator to immediately return that positive + value, indicating short-circuit success. The iterator can be + restarted at the next attribute. + <li>Negative causes the iterator to immediately return that value, + indicating failure. The iterator can be restarted at the next + attribute. + </ul> + <dd><b>attr_num, op, and op_data in SC are + attr_number, operator, and operator_data, respectively, in UG.</b> + <p> +<dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>loc_id</code> + <dd>IN: Object (dataset or group) to be iterated over + <dt><em>unsigned *</em> <code>attr_num</code> + <dd>IN/OUT: Starting (IN) & Ending (OUT) attribute number + <dt><em>H5A_operator_t</em> <code>op</code> + <dd>IN: User's function to pass each attribute to + <dt><em>void *</em><code>op_data</code> + <dd>IN/OUT: User's data to pass through to iterator operator function + </dl> +<dt><strong>Returns:</strong> + <dd>If successful, returns the return value of the last operator + if it was non-zero, or zero if all attributes were processed. + Otherwise returns FAIL (-1). +</dl> + + +<hr> +<dl> +<dt><strong>Name:</strong> <a name="Annot-Delete">H5Adelete</a> +<dt><strong>Signature:</strong> + <dd><em>herr_t</em> <code>H5Adelete</code>(<em>hid_t</em> <code>loc_id</code>, + <em>const char *</em><code>name</code> + ) +<dt><strong>Purpose:</strong> + <dd>Deletes an attribute from a location. +<dt><strong>Description:</strong> + <dd>SC: <code>H5Adelete</code> removes the named attribute from a dataset or group. + This function should not be used when attribute identifiers are open on 'loc_id' + as it may cause the internal indexes of the attributes to change and future + writes to the open attributes to produce incorrect results. + <p> + UG: <code>H5Adelete</code> removes the named attribute from a dataset or group. + This function should not be used when attribute identifiers are open on loc_id as + it may cause the internal indexes of the attributes to change and future + writes to the open attributes to produce incorrect results. + Returns non-negative on success, negative on failure. +<dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>loc_id</code> + <dd>IN: Object (dataset or group) to have attribute deleted from + <dt><em>const char *</em><code>name</code> + <dd>IN: Name of attribute to delete + </dl> +<dt><strong>Returns:</strong> + <dd>Returns SUCCEED (0) if successful; + otherwise FAIL (-1). +</dl> + + +<hr> +<dl> +<dt><strong>Name:</strong> <a name="Annot-Close">H5Aclose</a> +<dt><strong>Signature:</strong> + <dd><em>herr_t</em> <code>H5Aclose</code>(<em>hid_t</em> <code>attr_id</code>) +<dt><strong>Purpose:</strong> + <dd>Close an attribute identifier. +<dt><strong>Description:</strong> + <dd>SC: <code>H5Aclose</code> releases an attribute from use. Further use of the + attribute identifier will result in undefined behavior. + <p> + UG: <code>H5Aclose</code> releases an attribute from use. + Further use of the attribute identifier will result in undefined behavior. + This function returns non-negative on success, negative on failure. +<dt><strong>Parameters:</strong> + <dl> + <dt><em>hid_t</em> <code>attr_id</code> + <dd>IN: Attribute to release access to + </dl> +<dt><strong>Returns:</strong> + <dd>Returns SUCCEED (0) if successful; + otherwise FAIL (-1). +</dl> + + +<hr> + +<address> +<a href="mailto:fbaker@ncsa.uiuc.edu">Frank Baker</a> +<br> +<a href="mailto:h5docs@ncsa.uiuc.edu">HDF5 Documentation</a> + +<br> +Last modified: 6 July 1998 + +</body> +</html> |