Re: [Axis2] Patch - new functions to libxml2 wrapper

[Samisa Abeysinghe]

OK, So nabeel want to create the reader/writer in a different manner.
If that is the case, why not keep more or less the same API and add an 
optinal thir parameter (or a variable param list) to the create_for 
memory method of reader/writer?
This way, the impl details will be hidden from the user, and we could 
have the same API, wont cause problems raised by Sahan.
Samisa...
Sahan Gamage wrote:

Hi Nabeel,

Pls see my inline comments.

Nabeel wrote:

 

Sahan Gamage wrote:

   

Hi Nabeel,

What is this xmlDoc ? Is it libxml2 thing ? If so aren't we adding a
hard binding to Axis2C with libxml2 ?


     

  Yes, xmlDoc is libxml2 specific. But xmlDoc is hidden inside the
impls of the libxml2 wrapper to prevent hard binding.  (if you have a
look at the public interfaces axis2_xml_reader.h and
axis2_xml_writer.h you won't find any xmlDoc pointers)
   


Yes. I saw that. But the problem is where are you going to use it ? At
the point you are using these functions, say foo()is something similar
to this:

void foo()
{
   xmlDoc *doc = get_by_some_way();
   axis2_xml_reader_t *reader = NULL;
   ...
   reader = axis2_xml_reader_create_for_xml_doc(env, doc);
   ...
}
This code is pretty dependent on libxml2. So if this is for code for
axis2 as soon as we change the parser (to guththila or to any other pull
parser) the code will break unless we add a hard link dependancy for
libxml2. Isn't it ?

 

   Only catch is that the new functions are useful only when you are
using libxml2. If you are using some other xml parser library,
Guththila for example, you may not want to implement these new
prototypes in your wrapper.
   


My understanding is that wrpper is an interface to the common
functionality that every library that it wraps, can provide. So if
guththila can't provide this functionality we are breaking the rules of
wrapper. And the worst thing is we are exposing these libxml2 specific
stuff to the outside world by putting it to the public headers
axis2_xml_reader.h and axis2_xml_writer.h

 

thanks
-Nabeel

   

IMHO the wrapper is there to hide implemention specific (in this case
libxml2) details. If we expose the libxml2 things in the wrapper, the
idea of the wrapper is not there any more. Please clarify

- Sahan

Nabeel wrote:



     

The patch contains -
a new reader that reads a xmlDoc
a new writer that writes to a xmlDoc

(these methods are used by the php extension to prevent double
serialization when exchanging XML)

Please apply to svn.

thanks
-Nabeel

------------------------------------------------------------------------


Index: modules/xml/parser/libxml2/libxml2_writer_wrapper.c
===================================================================
--- modules/xml/parser/libxml2/libxml2_writer_wrapper.c    (revision
394906)
+++ modules/xml/parser/libxml2/libxml2_writer_wrapper.c    (working
copy)
@@ -34,6 +34,7 @@

#define AXIS2_LIBXML2_WRITER_MEMORY 1
#define AXIS2_LIBXML2_WRITER_FILE   2
+#define AXIS2_LIBXML2_WRITER_DOC    3

/************************ structures
*****************************************/

@@ -56,6 +57,8 @@
  xmlTextWriterPtr xml_writer;
     xmlBufferPtr buffer;
+
+    xmlDocPtr doc;
     int writer_type;
  @@ -262,6 +265,10 @@
axis2_char_t* AXIS2_CALL
axis2_libxml2_writer_wrapper_get_xml(axis2_xml_writer_t *writer,
                                   axis2_env_t **env);
+
+void* AXIS2_CALL
+axis2_libxml2_writer_wrapper_get_xml_doc(axis2_xml_writer_t *writer,
+                                                axis2_env_t **env);
                                   /*********************** static
functions ************************************/
static axis2_status_t
@@ -658,6 +665,180 @@
  return &(writer_impl->writer);
}

+/*********************** writer create func for file
***************************/
+
+AXIS2_DECLARE(axis2_xml_writer_t *)
+axis2_xml_writer_create_for_xml_doc(axis2_env_t **env,
+                                   axis2_char_t *encoding,
+                                   int is_prefix_default,
+                                   int compression)
+{
+    axis2_libxml2_writer_wrapper_impl_t *writer_impl = NULL;
+    AXIS2_ENV_CHECK(env, NULL);
+    writer_impl = (axis2_libxml2_writer_wrapper_impl_t
*)AXIS2_MALLOC((*env)->allocator,
+                   sizeof(axis2_libxml2_writer_wrapper_impl_t));
+    if(!writer_impl)
+    {
+        AXIS2_ERROR_SET((*env)->error, AXIS2_ERROR_NO_MEMORY,
AXIS2_FAILURE);
+        return NULL;
+    }
+    +    writer_impl->writer.ops = NULL;
+    writer_impl->encoding = NULL;
+    writer_impl->buffer = NULL;
+    writer_impl->in_empty_element = AXIS2_FALSE;
+    writer_impl->in_start_element = AXIS2_FALSE;
+    writer_impl->stack = NULL;
+    writer_impl->uri_prefix_map = NULL;
+    writer_impl->default_lang_namespace = NULL;
+    +    writer_impl->writer_type = AXIS2_LIBXML2_WRITER_DOC;
+    writer_impl->compression = compression;
+    +    +    /*writer_impl->buffer = xmlBufferCreate();
+    if(writer_impl->buffer == NULL)
+    {
+        axis2_libxml2_writer_wrapper_free(&(writer_impl->writer),
env);
+        AXIS2_ERROR_SET((*env)->error, AXIS2_ERROR_NO_MEMORY,
AXIS2_FAILURE);
+        return NULL;
+    }*/
+    +    writer_impl->xml_writer =
/*xmlNewTextWriterMemory(writer_impl->buffer, 0);*/
+                               
xmlNewTextWriterDoc(&writer_impl->doc, 0);
+    if(writer_impl->xml_writer == NULL)
+    {
+        axis2_libxml2_writer_wrapper_free(&(writer_impl->writer),
env);
+        AXIS2_ERROR_SET((*env)->error,
AXIS2_ERROR_CREATING_XML_STREAM_WRITER , AXIS2_FAILURE);
+        return NULL;
+    }
+
+     if(encoding)
+        writer_impl->encoding = AXIS2_STRDUP(encoding , env);
+    else
+        writer_impl->encoding = AXIS2_STRDUP(ENCODING, env);
+     +    +    writer_impl->uri_prefix_map = axis2_hash_make(env);
+    if(!(writer_impl->uri_prefix_map))
+    {
+        axis2_libxml2_writer_wrapper_free(&(writer_impl->writer),
env);
+        AXIS2_ERROR_SET((*env)->error, +           
AXIS2_ERROR_NO_MEMORY, AXIS2_FAILURE);
+        +        return NULL;
+    }
+    writer_impl->stack = axis2_stack_create(env);
+    if(!(writer_impl->stack))
+    {
+        axis2_libxml2_writer_wrapper_free(&(writer_impl->writer),
env);
+        AXIS2_ERROR_SET((*env)->error, +           
AXIS2_ERROR_NO_MEMORY, AXIS2_FAILURE);
+        return NULL;
+    }
+    +   
axis2_libxml2_writer_wrapper_set_default_lang_namespace(&(writer_impl->writer),
env);
+    +    writer_impl->writer.ops =
(axis2_xml_writer_ops_t*)AXIS2_MALLOC((*env)->allocator,
+                                    sizeof(axis2_xml_writer_ops_t));
+    if(!(writer_impl->writer.ops))
+    {
+        axis2_libxml2_writer_wrapper_free(&(writer_impl->writer),
env);
+        AXIS2_ERROR_SET((*env)->error, AXIS2_ERROR_NO_MEMORY,
AXIS2_FAILURE);
+        return NULL;
+    }
+    +    /* ops */
+    writer_impl->writer.ops->free = +           
axis2_libxml2_writer_wrapper_free;
+            +    writer_impl->writer.ops->write_start_element =
+            axis2_libxml2_writer_wrapper_write_start_element;
+            +   
writer_impl->writer.ops->write_start_element_with_namespace =
+           
axis2_libxml2_writer_wrapper_write_start_element_with_namespace;
+            +   
writer_impl->writer.ops->write_start_element_with_namespace_prefix =
+           
axis2_libxml2_writer_wrapper_write_start_element_with_namespace_prefix;
+    +    writer_impl->writer.ops->write_empty_element =
+            axis2_libxml2_writer_wrapper_write_empty_element;
+            +   
writer_impl->writer.ops->write_empty_element_with_namespace  =
+           
axis2_libxml2_writer_wrapper_write_empty_element_with_namespace;
+            +   
writer_impl->writer.ops->write_empty_element_with_namespace_prefix =
+           
axis2_libxml2_writer_wrapper_write_empty_element_with_namespace_prefix;
+    +    writer_impl->writer.ops->write_end_element = +           
axis2_libxml2_writer_wrapper_write_end_element;
+            +    writer_impl->writer.ops->write_end_document =
+            axis2_libxml2_writer_wrapper_write_end_document;
+    +    writer_impl->writer.ops->write_attribute = +           
axis2_libxml2_writer_wrapper_write_attribute;
+            +   
writer_impl->writer.ops->write_attribute_with_namespace =
+           
axis2_libxml2_writer_wrapper_write_attribute_with_namespace;
+            +   
writer_impl->writer.ops->write_attribute_with_namespace_prefix =
+           
axis2_libxml2_writer_wrapper_write_attribute_with_namespace_prefix;
+            +    writer_impl->writer.ops->write_namespace =
+            axis2_libxml2_writer_wrapper_write_namespace;
+            +    writer_impl->writer.ops->write_default_namespace =
+            axis2_libxml2_writer_wrapper_write_default_namespace;
+            +    writer_impl->writer.ops->write_comment =
+            axis2_libxml2_writer_wrapper_write_comment;
+            +   
writer_impl->writer.ops->write_processing_instruction = +           
axis2_libxml2_writer_wrapper_write_processing_instruction;
+            +   
writer_impl->writer.ops->write_processing_instruction_data =
+           
axis2_libxml2_writer_wrapper_write_processing_instruction_data;
+            +    writer_impl->writer.ops->write_cdata =
+            axis2_libxml2_writer_wrapper_write_cdata;
+            +    writer_impl->writer.ops->write_dtd = +           
axis2_libxml2_writer_wrapper_write_dtd;
+            +    writer_impl->writer.ops->write_entity_ref =
+            axis2_libxml2_writer_wrapper_write_entity_ref;
+            +    writer_impl->writer.ops->write_start_document =
+            axis2_libxml2_writer_wrapper_write_start_document;
+            +   
writer_impl->writer.ops->write_start_document_with_version =
+           
axis2_libxml2_writer_wrapper_write_start_document_with_version;
+            +   
writer_impl->writer.ops->write_start_document_with_version_encoding
= +           
axis2_libxml2_writer_wrapper_write_start_document_with_version_encoding;

+            +    writer_impl->writer.ops->write_characters =
+            axis2_libxml2_writer_wrapper_write_characters;
+            +    writer_impl->writer.ops->get_prefix =
+            axis2_libxml2_writer_wrapper_get_prefix;
+            +    writer_impl->writer.ops->set_prefix = +           
axis2_libxml2_writer_wrapper_set_prefix;
+            +    writer_impl->writer.ops->set_default_prefix =
+            axis2_libxml2_writer_wrapper_set_default_prefix;
+            +    writer_impl->writer.ops->write_encoded =
+            axis2_libxml2_writer_wrapper_write_encoded;
+            +    writer_impl->writer.ops->get_xml =
+            axis2_libxml2_writer_wrapper_get_xml_doc;
+                             +    return &(writer_impl->writer);
+}
+
/*******************************************************************************/

axis2_status_t AXIS2_CALL
axis2_libxml2_writer_wrapper_free(axis2_xml_writer_t *writer,
@@ -1561,6 +1742,26 @@
  return output;   }

+void* AXIS2_CALL
+axis2_libxml2_writer_wrapper_get_xml_doc(axis2_xml_writer_t *writer,
+                                        axis2_env_t **env)
+{
+    axis2_libxml2_writer_wrapper_impl_t *writer_impl = NULL;
+    writer_impl = AXIS2_INTF_TO_IMPL(writer);
+
+    if(writer_impl->xml_writer)
+    {
+        xmlFreeTextWriter(writer_impl->xml_writer);
+        writer_impl->xml_writer = NULL;
+    }
+
+    if (writer_impl->writer_type == AXIS2_LIBXML2_WRITER_DOC)
+    {
+        return (void*)writer_impl->doc;
+    }
+    return NULL;
+}
+
static axis2_status_t
axis2_libxml2_writer_wrapper_pop_context(axis2_xml_writer_t *writer,
                                       axis2_env_t **env)
Index: modules/xml/parser/libxml2/libxml2_reader_wrapper.c
===================================================================
--- modules/xml/parser/libxml2/libxml2_reader_wrapper.c    (revision
394906)
+++ modules/xml/parser/libxml2/libxml2_reader_wrapper.c    (working
copy)
@@ -555,6 +555,102 @@
                              return &(wrapper_impl->parser);
}
+
+
+/***************** create function for xmlDoc
************************/
+AXIS2_DECLARE(axis2_xml_reader_t *)
+axis2_xml_reader_create_for_xml_doc(axis2_env_t **env,
+                                    void *doc)
+{    +    axis2_libxml2_reader_wrapper_impl_t *wrapper_impl = NULL;
+    +    AXIS2_ENV_CHECK( env, NULL);
+        +    wrapper_impl =
(axis2_libxml2_reader_wrapper_impl_t*)AXIS2_MALLOC((*env)->allocator,
+         sizeof(axis2_libxml2_reader_wrapper_impl_t));
+    if(!wrapper_impl)
+    {
+        AXIS2_ERROR_SET((*env)->error, AXIS2_ERROR_NO_MEMORY,
AXIS2_FAILURE);
+        return NULL;   +    }
+    wrapper_impl->close_input_callback = NULL;
+    wrapper_impl->read_input_callback = NULL;
+    wrapper_impl->ctx = NULL;
+   
+    wrapper_impl->reader =  xmlReaderWalker((xmlDocPtr)doc);
+
+    if(!(wrapper_impl->reader))
+    {
+        AXIS2_FREE((*env)->allocator, wrapper_impl);
+        AXIS2_ERROR_SET((*env)->error, +               
AXIS2_ERROR_CREATING_XML_STREAM_READER, AXIS2_FAILURE);
+        return NULL;
+    }
+
+    /*xmlTextReaderSetErrorHandler(wrapper_impl->reader, +        
(xmlTextReaderErrorFunc)axis2_libxml2_reader_wrapper_error_handler,
+         (*env));
+    */
+    wrapper_impl->current_event = -1;
+    +    axis2_libxml2_reader_wrapper_init_map(wrapper_impl);
+    +    wrapper_impl->parser.ops = NULL;
+    wrapper_impl->parser.ops =
(axis2_xml_reader_ops_t*)AXIS2_MALLOC((*env)->allocator,
+                                sizeof(axis2_xml_reader_ops_t));
+    +    if(!(wrapper_impl->parser.ops))
+    {
+        xmlFreeTextReader(wrapper_impl->reader);
+        AXIS2_FREE((*env)->allocator, wrapper_impl);
+        AXIS2_ERROR_SET((*env)->error, AXIS2_ERROR_NO_MEMORY,
AXIS2_FAILURE);
+        return NULL;
+    }
+
+   
+    wrapper_impl->parser.ops->free =
axis2_libxml2_reader_wrapper_free;
+    wrapper_impl->parser.ops->next =
axis2_libxml2_reader_wrapper_next;
+    wrapper_impl->parser.ops->xml_free =
axis2_libxml2_reader_wrapper_xml_free;
+    +    wrapper_impl->parser.ops->get_attribute_count =
+        axis2_libxml2_reader_wrapper_get_attribute_count;
+    wrapper_impl->parser.ops->get_attribute_name_by_number =
+        axis2_libxml2_reader_wrapper_get_attribute_name_by_number;
+    wrapper_impl->parser.ops->get_attribute_value_by_number =
+        axis2_libxml2_reader_wrapper_get_attribute_value_by_number;
+    wrapper_impl->parser.ops->get_attribute_namespace_by_number =
+       
axis2_libxml2_reader_wrapper_get_attribute_namespace_by_number;
+    wrapper_impl->parser.ops->get_attribute_prefix_by_number =
+        axis2_libxml2_reader_wrapper_get_attribute_prefix_by_number;
+    +    wrapper_impl->parser.ops->get_value =
+        axis2_libxml2_reader_wrapper_get_value;
+    wrapper_impl->parser.ops->get_prefix =
+        axis2_libxml2_reader_wrapper_get_prefix;
+    wrapper_impl->parser.ops->get_name =
+        axis2_libxml2_reader_wrapper_get_name;
+        +        +    wrapper_impl->parser.ops->get_namespace_count =
+        axis2_libxml2_reader_wrapper_get_namespace_count;
+    wrapper_impl->parser.ops->get_namespace_prefix_by_number =
+        axis2_libxml2_reader_wrapper_get_namespace_prefix_by_number;
+    wrapper_impl->parser.ops->get_namespace_uri_by_number =
+        axis2_libxml2_reader_wrapper_get_namespace_uri_by_number;
+        +    wrapper_impl->parser.ops->get_pi_target =
+        axis2_libxml2_reader_wrapper_get_pi_target;
+    wrapper_impl->parser.ops->get_pi_data =
+        axis2_libxml2_reader_wrapper_get_pi_data;
+        +    wrapper_impl->parser.ops->get_dtd =
+        axis2_libxml2_reader_wrapper_get_dtd;
+        +    wrapper_impl->parser.ops->get_char_set_encoding =
+        axis2_libxml2_reader_wrapper_get_char_set_encoding;
+
+    return &(wrapper_impl->parser);
+}
/****************** end create functions
***************************************/

int AXIS2_CALL
Index: include/axis2_xml_reader.h
===================================================================
--- include/axis2_xml_reader.h    (revision 394906)
+++ include/axis2_xml_reader.h    (working copy)
@@ -355,6 +355,9 @@
                                int size,
                                const axis2_char_t *encoding);

+AXIS2_DECLARE(axis2_xml_reader_t *)
+axis2_xml_reader_create_for_xml_doc(axis2_env_t **env,
+                                    void *doc);   
/**
* init function initializes the parser */
Index: include/axis2_xml_writer.h
===================================================================
--- include/axis2_xml_writer.h    (revision 394906)
+++ include/axis2_xml_writer.h    (working copy)
@@ -464,6 +464,12 @@
                                 int is_prefix_default,
                                 int compression);

+AXIS2_DECLARE(axis2_xml_writer_t *)
+    axis2_xml_writer_create_for_xml_doc(axis2_env_t **env,
+                                   axis2_char_t *encoding,
+                                   int is_prefix_default,
+                                   int compression);
+   
/********************** start macros
*******************************************/

#define AXIS2_XML_WRITER_FREE(writer, env) \