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author | David Sommerseth <davids@redhat.com> | 2009-04-28 11:12:58 +0200 |
---|---|---|
committer | David Sommerseth <davids@redhat.com> | 2009-04-29 11:22:12 +0200 |
commit | c7be629d44d4e2be6c8116796714e0042a977885 (patch) | |
tree | a126396444123f0b9aa505f8a8d675838af73458 /src | |
parent | 70e35765fbb9be6ddd6aab6555916777a593e0aa (diff) | |
download | python-dmidecode-c7be629d44d4e2be6c8116796714e0042a977885.tar.gz python-dmidecode-c7be629d44d4e2be6c8116796714e0042a977885.tar.xz python-dmidecode-c7be629d44d4e2be6c8116796714e0042a977885.zip |
Added generic XML -> Python parser
The xmlpythonizer module will convert any XML data (xmlNode
or xmlDoc) and format it as a Python object. The formatting is
defined in it's own XML file.
Basic format:
<dmidecode_fieldmap version="1">
<Mapping name="{name of mapping table}">
<Map keytype="{key type}" key="{key value}"
valuetype="{value type} value="{value}"/>
</Mapping>
</dmidecode_fieldmap>
The keytype and key attributes defines the key in the Python Dict. The
root element will always be a Python Dict structure. The valid key types
are:
* constant
Uses the value in {key} as the key value
* string, integer, float
Uses a string value from the data XML to be converted to Python. The
value set in the key attribute defines an XPath value which points to the
data to be used as a Python dict key.
Since Python only supports C strings in the C interface for Python dict
keys, integer and float will be treated as strings.
The valuetype and value attributes are similar to the keys, but with some more
features. Valid valuetypes are:
* constant
The value given in the value attribute will be used in the value in
the Python result.
* string, integer, float
The value given in the value attribute defines the XPath to the data XML,
of where to retrieve the value for the given key.
The valuetype defines if the data should be understood as a string, integer
or float in the Python result.
* list:string, list:integer, list:float
This does the same as the string, integer or float type, with a tweak. The
data will be put into a list. If the XPath given returns multiple nodes,
all of them will be added to this list.
* dict
The dict valuetype is more special. It should not contain any value
attribute. On the other hand, it should contain a sub-level of <Map> tags.
In this way, you can build up a multi dimensional Python dict.
Example:
** pythonmap.xml **
<?xml version="1.0" encoding="UTF-8"?>
<dmidecode_fieldmap version="1">
<Mapping name="example_map">
<Map keytype="constant" key="DemoCase" valuetype="constant" value="XML Pythonizing"/>
<Map keytype="constant" key="String1" valuetype="string" value="/example/string1"/>
<Map keytype="constant" key="AttribString1" valuetype="integer" value="/example/string1/@int_value"/>
<Map keytype="string" key="/example/keyset/@value" valuetype="dict">
<Map keytype="constant" key="Value1" valuetype="string" value="/example/keyset/value1"/>
<Map keytype="constant" key="ValueList" valuetype="list:string" value="/example/keyset/valuelist"/>
</Map>
</Mapping>
</dmidecode_fieldmap>
** exampledata.xml **
<?xml version="1.0" encoding="UTF-8"?>
<example>
<string1 int_value="1234">String value #1</string1>
<keyset value="TestData">
<value1>More test data</value1>
<valuelist>Value1 in list</valuelist>
<valuelist>Value2 in list</valuelist>
<valuelist>Value3 in list</valuelist>
</keyset>
</example>
** C code snippet **
void xmlpythonizer() {
xmlDoc *xmlmap = NULL;
xmlDoc *xmldata = NULL;
ptzMAP *mapping = NULL;
PyObject *pythondata = NULL;
// Read XML files
xmlmap = xmlReadFile("pythonmap.xml", NULL, 0);
xmldata = xmlReadFile("exampledata.xml", NULL, 0);
// Parse the mapping XML
mapping = dmiMAP_ParseMappingXML(xmlmap, "example_map");
// Parse the xmldata into a Python object
pythondata = pythonizeXMLdoc(mapping, xmldata);
// ..... the program continues to do something useful
}
The result stored inside the pythondata object should now be
something similar to:
{'DemoCase': 'XML Pythonizing',
'String1': 'String value #1',
'AttribString1: 1234,
'TestData': {'Value1': 'More test data',
'ValueList': ['Value1 in list','Value2 in list','Value3 in list']}
}
Diffstat (limited to 'src')
-rw-r--r-- | src/pythonmap.xml | 16 | ||||
-rw-r--r-- | src/setup.py | 3 | ||||
-rw-r--r-- | src/xmlpythonizer.c | 522 | ||||
-rw-r--r-- | src/xmlpythonizer.h | 50 |
4 files changed, 590 insertions, 1 deletions
diff --git a/src/pythonmap.xml b/src/pythonmap.xml new file mode 100644 index 0000000..a49a8ab --- /dev/null +++ b/src/pythonmap.xml @@ -0,0 +1,16 @@ +<?xml version="1.0" encoding="UTF-8"?> +<dmidecode_fieldmap version="1"> + <Mapping name="BIOSLanguage"> + <Map keytype="string" key="/BIOSlanguage/@handle" valuetype="dict"> + <Map keytype="constant" key="data" valuetype="dict"> + <Map keytype="constant" key="Currently Installed Language" + valuetype="list:string" value="/BIOSlanguage/Installed/Language"/> + <Map keytype="constant" key="Installed Languages" + valuetype="integer" value="/BIOSlanguage/@installable_languages"/> + </Map> + <Map keytype="constant" key="dmi_type" valuetype="integer" value="/BIOSlanguage/@type"/> + <Map keytype="constant" key="dmi_handle" valuetype="string" value="/BIOSlanguage/@handle"/> + <Map keytype="constant" key="dmi_size" valuetype="integer" value="/BIOSlanguage/@size"/> + </Map> + </Mapping> +</dmidecode_fieldmap> diff --git a/src/setup.py b/src/setup.py index 6272e85..ec66c3f 100644 --- a/src/setup.py +++ b/src/setup.py @@ -16,7 +16,8 @@ setup( "src/util.c", "src/dmioem.c", "src/dmidecode.c", - "src/dmixml.c" + "src/dmixml.c", + "src/xmlpythonizer.c" ], include_dirs = [ "/usr/include/libxml2" ], library_dirs = [ "/home/nima/dev-room/projects/dmidecode" ], diff --git a/src/xmlpythonizer.c b/src/xmlpythonizer.c new file mode 100644 index 0000000..92e0d7f --- /dev/null +++ b/src/xmlpythonizer.c @@ -0,0 +1,522 @@ +/* Converts XML docs and nodes to Python dicts and lists by + * using an XML file which describes the Python dict layout + * + * Copyright 2009 David Sommerseth <davids@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * For the avoidance of doubt the "preferred form" of this code is one which + * is in an open unpatent encumbered format. Where cryptographic key signing + * forms part of the process of creating an executable the information + * including keys needed to generate an equivalently functional executable + * are deemed to be part of the source code. + */ + +#include <Python.h> + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> + +#include <libxml/tree.h> +#include <libxml/xpath.h> + +#include "dmixml.h" +#include "xmlpythonizer.h" + +ptzMAP *ptzmap_Add(const ptzMAP *chain, + ptzTYPES ktyp, const char *key, + ptzTYPES vtyp, const char *value, + ptzMAP *child) +{ + ptzMAP *ret = NULL; + + assert( (ktyp == ptzCONST) || (ktyp == ptzSTR) || (ktyp == ptzINT) || (ktyp == ptzFLOAT) ); + assert( key != NULL ); + // Make sure that value and child are not used together + assert( ((value == NULL) && child != NULL) || ((value != NULL) && (child == NULL)) ); + + ret = (ptzMAP *) malloc(sizeof(ptzMAP)+2); + assert( ret != NULL ); + memset(ret, 0, sizeof(ptzMAP)+2); + + ret->type_key = ktyp; + ret->key = strdup(key); + + ret->type_value = vtyp; + if( value != NULL ) { + ret->value = strdup(value); + ret->child = NULL; + } else if( child != NULL ) { + ret->value = NULL; + ret->child = child; + } + + if( chain != NULL ) { + ret->next = (ptzMAP *) chain; + } + return ret; +}; + +#define ptzmap_Free(ptr) { ptzmap_Free_func(ptr); ptr = NULL; } +void ptzmap_Free_func(ptzMAP *ptr) +{ + if( ptr == NULL ) { + return; + } + + free(ptr->key); + ptr->key = NULL; + + if( ptr->value != NULL ) { + free(ptr->value); + ptr->value = NULL; + } + + if( ptr->child != NULL ) { + ptzmap_Free(ptr->child); + } + if( ptr->next != NULL ) { + ptzmap_Free(ptr->next); + } + free(ptr); +} + + +#if 1 +// DEBUG FUNCTIONS +static const char *ptzTYPESstr[] = { "ptzCONST", "ptzSTR", "ptzINT", "ptzFLOAT", + "ptzLIST_STR", "ptzLIST_INT", "ptzLIST_FLOAT", + "ptzDICT", NULL }; + +void indent(int lvl) +{ + int i = 0; + if( lvl == 0 ) { + return; + } + + for( i = 0; i < (lvl * 3); i++ ) { + printf(" "); + } +} + +#define ptzmap_Dump(ptr) { ptzmap_Dump_func(ptr, 0); } +void ptzmap_Dump_func(const ptzMAP *ptr, int level) +{ + if( ptr == NULL ) { + return; + } + + indent(level); printf("key type: (%i) %-13.13s - key: %s\n", + ptr->type_key, ptzTYPESstr[ptr->type_key], ptr->key); + indent(level); printf("value type: (%i) %-13.13s - value: %s\n", + ptr->type_value, ptzTYPESstr[ptr->type_value], ptr->value); + if( ptr->child != NULL ) { + indent(level); printf(" ** CHILD\n"); + ptzmap_Dump_func(ptr->child, level + 1); + indent(level); printf(" ** ---------\n"); + } + if( ptr->next != NULL ) { + printf("\n"); + ptzmap_Dump_func(ptr->next, level); + } +} +#endif // END OF DEBUG FUNCTIONS + +// +// Parser for the XML -> Python mapping XML file +// +// This mappipng XML file describes how the Python result +// should look like and where it should pick the data from +// when later on parsing the dmidecode XML data. +// + +// Valid key and value types for the mapping file +inline ptzTYPES _convert_maptype(const char *str) { + if( strcmp(str, "string") == 0 ) { + return ptzSTR; + } else if( strcmp(str, "constant") == 0 ) { + return ptzCONST; + } else if( strcmp(str, "integer") == 0 ) { + return ptzINT; + } else if( strcmp(str, "float") == 0 ) { + return ptzFLOAT; + } else if( strcmp(str, "list:string") == 0 ) { + return ptzLIST_STR; + } else if( strcmp(str, "list:integer") == 0 ) { + return ptzLIST_INT; + } else if( strcmp(str, "list:float") == 0 ) { + return ptzLIST_FLOAT; + } else if( strcmp(str, "dict") == 0 ) { + return ptzDICT; + } else { + fprintf(stderr, "Unknown field type: %s - defaulting to 'string'\n", str); + return ptzSTR; + } +} + +// Internal parser +ptzMAP *_do_dmimap_parsing(xmlNode *node) { + ptzMAP *retmap = NULL; + xmlNode *ptr_n = NULL, *map_n = NULL;; + + // Go to the next XML_ELEMENT_NODE + for( map_n = node; map_n != NULL; map_n = map_n->next ) { + if( map_n->type == XML_ELEMENT_NODE ) { + break; + } + } + if( map_n == NULL ) { + return NULL; + } + + // Go to the first <Map> node + if( xmlStrcmp(node->name, (xmlChar *) "Map") != 0 ) { + map_n = dmixml_FindNode(node, "Map"); + if( map_n == NULL ) { + return NULL; + } + } + + // Loop through it's children + for( ptr_n = map_n ; ptr_n != NULL; ptr_n = ptr_n->next ) { + ptzTYPES type_key, type_value; + char *key = NULL, *value = NULL; + + if( ptr_n->type != XML_ELEMENT_NODE ) { + continue; + } + + // Get the attributes defining key, keytype, value and valuetype + key = dmixml_GetAttrValue(ptr_n, "key"); + type_key = _convert_maptype(dmixml_GetAttrValue(ptr_n, "keytype")); + + value = dmixml_GetAttrValue(ptr_n, "value"); + type_value = _convert_maptype(dmixml_GetAttrValue(ptr_n, "valuetype")); + + if( type_value == ptzDICT ) { + // When value type is ptzDICT, traverse the children nodes + // - should contain another Map set instead of a value attribute + if( ptr_n->children == NULL ) { + continue; + } + // Recursion + retmap = ptzmap_Add(retmap, type_key, key, type_value, NULL, + _do_dmimap_parsing(ptr_n->children->next)); + } else { + // Append the value as a normal value when the + // value type is not a Python Dict + retmap = ptzmap_Add(retmap, type_key, key, type_value, value, NULL); + } + value = NULL; + key = NULL; + } + return retmap; +} + +// Main parser function for the mapping XML +ptzMAP *dmiMAP_ParseMappingXML(xmlDoc *xmlmap, const char *mapname) { + ptzMAP *map = NULL; + xmlNode *node = NULL; + + // Find the root tag and locate our mapping + node = xmlDocGetRootElement(xmlmap); + assert( node != NULL ); + + // Verify that the root node got the right name + if( (node == NULL) + || (xmlStrcmp(node->name, (xmlChar *) "dmidecode_fieldmap") != 0 )) { + fprintf(stderr, "Invalid XML-Python mapping file\n"); + return NULL; + } + + // Verify that it's of a version we support + if( strcmp(dmixml_GetAttrValue(node, "version"), "1") != 0 ) { + fprintf(stderr, "Unsupported XML-Python mapping file format\n"); + return NULL; + } + + // Find the <Mapping> section matching our request (mapname) + for( node = node->children->next; node != NULL; node = node->next ) { + if( xmlStrcmp(node->name, (xmlChar *) "Mapping") == 0) { + char *name = dmixml_GetAttrValue(node, "name"); + if( (name != NULL) && (strcmp(name, mapname) == 0) ) { + break; + } + } + } + + if( node == NULL ) { + fprintf(stderr, "No mapping for '%s' was found " + "in the XML-Python mapping file\n", mapname); + return NULL; + } + + // Start creating an internal map structure based on the mapping XML. + map = _do_dmimap_parsing(node); + + return map; +} + + +// +// Parser routines for converting XML data into Python structures +// + +inline PyObject *StringToPyObj(ptzTYPES type, const char *str) { + PyObject *value; + + switch( type ) { + case ptzINT: + case ptzLIST_INT: + value = PyInt_FromLong((str != NULL ? atoi(str) : 0)); + break; + + case ptzFLOAT: + case ptzLIST_FLOAT: + value = PyFloat_FromDouble((str != NULL ? atof(str) : 0)); + break; + + case ptzSTR: + case ptzLIST_STR: + value = PyString_FromString(str); + break; + + default: + fprintf(stderr, "Invalid type '%i' for value '%s'\n", type, str); + value = Py_None; + } + return value; +} + + +// Retrieve a value from the XML doc (XPath Context) based on a XPath query +xmlXPathObject *_get_xpath_values(xmlXPathContext *xpctx, const char *xpath) { + xmlChar *xp_xpr = NULL; + xmlXPathObject *xp_obj = NULL; + + if( xpath == NULL ) { + return NULL; + } + + xp_xpr = xmlCharStrdup(xpath); + xp_obj = xmlXPathEvalExpression(xp_xpr, xpctx); + assert( xp_obj != NULL ); + free(xp_xpr); + + if( (xp_obj->nodesetval == NULL) || (xp_obj->nodesetval->nodeNr == 0) ) { + xmlXPathFreeObject(xp_obj); + return NULL; + } + + return xp_obj; +} + +// Internal XML parser routine, which traverses the given mapping table, +// returning a Python structure accordingly to the map. +PyObject *_do_pythonizeXML(ptzMAP *in_map, xmlXPathContext *xpctx, int lvl) { + ptzMAP *map_p = NULL; + PyObject *retdata = NULL; + int i = 0; + + retdata = PyDict_New(); + for( map_p = in_map; map_p != NULL; map_p = map_p->next ) { + xmlXPathObject *xpobj = NULL; + char *key = NULL; + PyObject *value = NULL; + + // Get key value + switch( map_p->type_key ) { + case ptzCONST: + key = map_p->key; + break; + + case ptzSTR: + case ptzINT: + case ptzFLOAT: + xpobj = _get_xpath_values(xpctx, map_p->key); + if( xpobj != NULL ) { + key = dmixml_GetContent(xpobj->nodesetval->nodeTab[0]); + xmlXPathFreeObject(xpobj); + } + break; + default: + fprintf(stderr, "Unknown key type: %i\n", map_p->type_key); + return Py_None; + break; + } + + // Get 'value' value + switch( map_p->type_value ) { + case ptzCONST: + value = PyString_FromString(map_p->value); + break; + + case ptzSTR: + case ptzINT: + case ptzFLOAT: + xpobj = _get_xpath_values(xpctx, map_p->value); + if( xpobj != NULL ) { + value = StringToPyObj(map_p->type_value, + dmixml_GetContent(xpobj->nodesetval->nodeTab[0])); + xmlXPathFreeObject(xpobj); + } + break; + + case ptzLIST_STR: + case ptzLIST_INT: + case ptzLIST_FLOAT: + xpobj = _get_xpath_values(xpctx, map_p->value); + value = PyList_New(0); + if( xpobj != NULL ) { + for( i = 0; i < xpobj->nodesetval->nodeNr; i++ ) { + char *valstr = dmixml_GetContent(xpobj->nodesetval->nodeTab[i]); + PyList_Append(value, StringToPyObj(map_p->type_value, valstr)); + } + xmlXPathFreeObject(xpobj); + } + break; + + case ptzDICT: + // Traverse the children to get the value of this element + value = _do_pythonizeXML(map_p->child, xpctx, lvl+1); + Py_DECREF(value); + break; + + default: + fprintf(stderr, "Unknown value type: %i\n", map_p->type_value); + free(key); key = NULL; + return Py_None; + break; + } + + PyDict_SetItemString(retdata, key, value); + Py_DECREF(value); + } + Py_INCREF(retdata); + return retdata; +} + +// Convert a xmlDoc to a Python object, based on the given map +PyObject *pythonizeXMLdoc(ptzMAP *map, xmlDoc *xmldoc) +{ + xmlXPathContext *xp_ctx = NULL; + PyObject *retdata = NULL; + + // Prepare a XPath context for XPath queries + xp_ctx = xmlXPathNewContext(xmldoc); + assert( xp_ctx != NULL ); + + // Parse the XML and create Python data + retdata = _do_pythonizeXML(map, xp_ctx, 0); + + // Clean up and return data + xmlXPathFreeContext(xp_ctx); + + return retdata; +} + +// Convert a xmlNode to a Python object, based on the given map +PyObject *pythonizeXMLnode(ptzMAP *map, xmlNode *nodes) +{ + xmlDoc *xmldoc = NULL; + PyObject *retdata = NULL; + + // Create our own internal XML doc and + // copy over the input nodes to our internal doc. + // This is needed as the XPath parser in libxml2 + // only works with xmlDoc. + xmldoc = xmlNewDoc((xmlChar *) "1.0"); + assert( xmldoc != NULL ); + xmlDocSetRootElement(xmldoc, xmlCopyNode(nodes, 1)); + + // Parse the internal xmlDoc + retdata = pythonizeXMLdoc(map, xmldoc); + + // Clean up and return data + xmlFreeDoc(xmldoc); + return retdata; +} + + + +#if 0 +// Simple independent main function - only for debugging +int main() { + xmlDoc *doc = NULL; + ptzMAP *map = NULL; + + doc = xmlReadFile("pythonmap.xml", NULL, 0); + assert( doc != NULL ); + + map = dmiMAP_ParseMappingXML(doc, "BIOSLanguage"); + ptzmap_Dump(map); + + ptzmap_Free(map); + xmlFreeDoc(doc); + + return 0; +} +#endif + +#if 0 +// Simple test module for Python - only for debugging +PyObject* demo_xmlpy() +{ + xmlDoc *doc = NULL, *mapping_xml = NULL; + ptzMAP *mapping = NULL; + PyObject *ret = NULL; + + // Read the XML-Python mapping setup + mapping_xml = xmlReadFile("pythonmap.xml", NULL, 0); + assert( mapping_xml != NULL ); + + mapping = dmiMAP_ParseMappingXML(mapping_xml, "BIOSLanguage"); + assert( mapping != NULL ); + + // Read XML data from file + doc = xmlReadFile("test.xml", NULL, 0); + assert( doc != NULL ); + + // Create a PyObject out of the XML indata + ret = pythonizeXMLdoc(mapping, doc); + + // Clean up and return the data + ptzmap_Free(mapping); + xmlFreeDoc(doc); + xmlFreeDoc(mapping_xml); + + return ret; +} + + +static PyMethodDef DemoMethods[] = { + {"xmlpy", demo_xmlpy, METH_NOARGS, ""}, + {NULL, NULL, 0, NULL} +}; + +PyMODINIT_FUNC initxmlpythonizer(void) { + PyObject *module = + Py_InitModule3((char *)"xmlpythonizer", DemoMethods, + "XML to Python Proof-of-Concept Python Module"); + + PyObject *version = PyString_FromString("2.10"); + Py_INCREF(version); + PyModule_AddObject(module, "version", version); +} +#endif // Python test module + diff --git a/src/xmlpythonizer.h b/src/xmlpythonizer.h new file mode 100644 index 0000000..4882d81 --- /dev/null +++ b/src/xmlpythonizer.h @@ -0,0 +1,50 @@ +/* Converts XML docs and nodes to Python dicts and lists by + * using an XML file which describes the Python dict layout + * + * Copyright 2009 David Sommerseth <davids@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * For the avoidance of doubt the "preferred form" of this code is one which + * is in an open unpatent encumbered format. Where cryptographic key signing + * forms part of the process of creating an executable the information + * including keys needed to generate an equivalently functional executable + * are deemed to be part of the source code. + */ + +#ifndef _XMLPYTHONIZER_H +#define _XMLPYTHONIZER_H + +typedef enum ptzTYPES_e { ptzCONST, ptzSTR, ptzINT, ptzFLOAT, + ptzLIST_STR, ptzLIST_INT, ptzLIST_FLOAT, + ptzDICT } ptzTYPES; + +typedef struct ptzMAP_s { + ptzTYPES type_key; // Valid types: ptzCONST, ptzSTR, ptzINT, ptzFLOAT + char *key; // for ptzCONST key contains a static string, other types an XPath to XML data + ptzTYPES type_value; + char *value; // for ptzCONST key contains a static string, + // the rest of types, an XPath to XML data + struct ptzMAP_s *child; // Only used for type_value == pyDICT + struct ptzMAP_s *next; // Pointer chain + +} ptzMAP; + + +ptzMAP *dmiMAP_ParseMappingXML(xmlDoc *xmlmap, const char *mapname); +PyObject *pythonizeXMLdoc(ptzMAP *map, xmlDoc *xmldoc); +PyObject *pythonizeXMLnode(ptzMAP *map, xmlNode *nodes); + +#endif // _XMLPYTHONIZER_H |