57b6dce6bf
- Added initial version of sicsget. This is a more generalised way of reading and writing SICS data wherever it is. The thing is extendable if reading something the current way is to slow. This has both a C interface and an interpreter interface.
119 lines
3.0 KiB
C
119 lines
3.0 KiB
C
/**
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* An implementation for a message pipe system as described in
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*
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* http://eventuallyconsistent.net/2013/08/14/messaging-as-a-programming-model-part-2/
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*
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* A message is passed through a series of filter routines which do things.
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*
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* Rather then loops I try using recursion here.
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*
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* copyright: GPL Copyleft
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*
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* Mark Koennecke, November 2013
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*/
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#include <stdlib.h>
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#include <string.h>
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#include <assert.h>
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#include <messagepipe.h>
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/*--------------------------------------------------------------------------------*/
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typedef struct __MessagePipe {
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void *userData;
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mpUserKill killFunc;
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mpFilterFunc filterFunc;
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struct __MessagePipe *next;
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struct __MessagePipe *previous;
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} MessagePipe;
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/*--------------------------------------------------------------------------------*/
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static int EmptyFunc(void *message, void *userData)
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{
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return MPCONTINUE;
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}
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/*---------------------------------------------------------------------------------*/
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pMP MakeMP()
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{
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pMP result = NULL;
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result = malloc(sizeof(MessagePipe));
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if(result != NULL){
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memset(result,0,sizeof(MessagePipe));
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result->filterFunc = EmptyFunc;
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}
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return result;
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}
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/*---------------------------------------------------------------------------------*/
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void KillMP(pMP self)
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{
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if(self == NULL){
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return;
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}
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pMP next = self->next;
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if(self->userData != NULL && self->killFunc != NULL){
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self->killFunc(self->userData);
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}
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free(self);
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KillMP(next);
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}
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/*-----------------------------------------------------------------------------------*/
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int AppendMPFilter(pMP self, mpFilterFunc func, void *userData, mpUserKill usKill)
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{
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assert(self != NULL);
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assert(func != NULL);
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if(self->next == NULL){
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self->next = malloc(sizeof(MessagePipe));
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if(self->next != NULL){
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self->next->previous = self;
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self->next->next = NULL;
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self->next->userData = userData;
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self->next->killFunc = usKill;
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self->next->filterFunc = func;
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return 0;
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} else {
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return 1;
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}
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} else {
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return AppendMPFilter(self->next, func, userData, usKill);
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}
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}
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/*-----------------------------------------------------------------------------------*/
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pMP PrependMPFilter(pMP self, mpFilterFunc func, void *userData, mpUserKill usKill)
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{
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pMP result = NULL;
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assert(func != NULL);
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result = malloc(sizeof(MessagePipe));
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if(result != NULL){
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result->userData = userData;
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result->killFunc = usKill;
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result->filterFunc = func;
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result->next = self;
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result->previous = NULL;
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return result;
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} else {
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/*
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we are ignoring an error here.........
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*/
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return self;
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}
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}
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/*-----------------------------------------------------------------------------------*/
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int MPprocess(pMP self, void *message)
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{
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int status;
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if(self == NULL || self->filterFunc == NULL){
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return MPCONTINUE;
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} else {
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status = self->filterFunc(message, self->userData);
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if(status == MPSTOP){
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return status;
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} else {
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return MPprocess(self->next, message);
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}
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}
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}
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