Appendix C. Sproc Specific Layer Rules

Assume that a message definition is given in Sproc Interface Format, defined in Appendix D. The algorithm below handles only one message, but is modified in a straightforward way to accomodate multiple messages. Alias types are not explicitly handled below.

Let:

• a message msg be defined as {msg_name, params};
  
• msg_name be a NULL-terminated string;
  
• Each element params, say params_i, be defined as {param_name_i, value_i, type_i};
  
• param_name_i be a NULL-terminated string; and,
  
• each element of type_i be one of "simple", "static array", "dyanmic array", "structure", "list", or "pointer".
  

Also, in the algorithm, let:

• stringify (value, type) be an operation that returns a NULL-terminated string that corresponds to an ASCII representation of value, interpreted as a parameter of type type; and,
  
• new_param (param_name) be an operation that tags the head object with an attribute "param_param_name";
  
• add_val (i, param_name, value, type) be an operation that either:
  • Adds the value "vali_" + stringify (value, type) to the attribute "param_param_name", or does the following:
    • Allocates a new structural object;
    • Generates an integer unique with respect to the message being processed;
    • Tags the new object with an attribute index with the value stringify (index, simple);
    • Adds the value "indexi_index" to the attribute "param_param_name"; and,
    • Sets the content of the new object to value.

Given msg, do:

1. Allocate a structural object, hereafter referred to as the "head" object
2. Tag the head object with an attribute "message_name" with the value msg_name
3. For each param params_i, do:

3.1 add_param (0, param_name_i, value_i, type_i) (defined below)

where add_param (num, param_name, value, type) is defined as:

1. new_param (param_name)
2. If type is "simple", then

2.1 add_val (num, param_name, value, type)
3. If type is "pointer", then

3.1 add_val (num, param_name, derefd_value, derefd_type), where derefd_value is the value of the pointer dereferenced, and derefd_type is the type of the variable to which this parameter points.
4. If type is "static array" or "dyanmic array", then

4.1 For each element value_i of the array, do:
4.1.1 add_param (i, param_name, value_i, base_type) (where base_type is the type of the elements in the array
5. If type is "structure", then

5.1 For each field field_i = {field_name_i, field_type_i, field_value_i} of the structure, do:
5.1.1 add_param (0, param_name+field_name, field_value_i, field_type)
6. If type is "list", then

6.1 Set i to 0.
6.2 For each list node in the list:
6.2.1 add_param (i, param_name, value_i, "structure"), where value_i is a structure containing all but the next field of the type definition
6.2.2 Increment i

Contents

Top
1. Introduction
2. Scope of the OHSWG...
3. Scenarios...
4. An OHS Reference Architecture Proposal...
5. An OHP Proposal...
6. Metacommentary
7. Conclusions
References
Appendix A. Generic Encoding Layer Rules
Appendix B. Sproc Generic Layer Rules
Appendix C. Sproc Specific Layer Rules
Appendix D. Sproc Interface Format
Appendix E. Current Protocol Proposal in Sproc Interface Format