Support infrastructure for simpler xml handler.

src/xml-rpc.c

@@ -5,6 +5,7 @@
  */
 
 #include <stdio.h>
+#include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
@@ -16,23 +17,142 @@
 #include "webserver.h"
 
 /* typedefs */
+typedef struct tag_xmlstack {
+    char *tag;
+    struct tag_xmlstack *next;
+} XMLSTACK;
+
 typedef struct tag_xmlstruct {
+    WS_CONNINFO *pwsc;
+    int stack_level;
+    XMLSTACK stack;    
 } XMLSTRUCT;
 
 /* Forwards */
 void xml_get_stats(WS_CONNINFO *pwsc);
 char *xml_entity_encode(char *original);
 
+XMLSTRUCT *xml_init(WS_CONNINFO *pwsc, int emit_header);
+void xml_push(XMLSTRUCT *pxml, char *term);
+void xml_pop(XMLSTRUCT *pxml);
+void xml_output(XMLSTRUCT *pxml, char *section, char *fmt, ...);
+void xml_deinit(XMLSTRUCT *pxml);
+
 /**
  * create an xml response structure, a helper struct for
  * building xml responses.
  *
+ * @param pwsc the pwsc we are emitting to
+ * @param emit_header whether or not to throw out html headers and xml header
  * @returns XMLSTRUCT on success, or NULL if failure
  */
-XMLSTRUCT *xml_init(void) {
+XMLSTRUCT *xml_init(WS_CONNINFO *pwsc, int emit_header) {
+    XMLSTRUCT *pxml;
+    
+    pxml=(XMLSTRUCT*)malloc(sizeof(XMLSTRUCT));
+    if(!pxml) {
+        DPRINTF(E_FATAL,L_XML,"Malloc error\n");
+    }
+    
+    memset(pxml,0,sizeof(XMLSTRUCT));
+    
+    pxml->pwsc = pwsc;
+    
+    if(emit_header) {
+        ws_addresponseheader(pwsc,"Content-Type","text/xml; charset=utf-8");
+        ws_writefd(pwsc,"HTTP/1.0 200 OK\r\n");
+        ws_emitheaders(pwsc);
+
+        ws_writefd(pwsc,"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>");
+    }
+    
+    return pxml;
 }
 
- 
+/**
+ * push a new term on the stack
+ *
+ * @param pxml xml struct obtained from xml_init
+ * @param term next xlm section to start 
+ */
+void xml_push(XMLSTRUCT *pxml, char *term) {
+    XMLSTACK *pstack;
+    
+    pstack = (XMLSTACK *)malloc(sizeof(XMLSTACK));
+    pstack->next=pxml->stack.next;
+    pstack->tag=strdup(term);
+    pxml->stack.next=pstack;
+    
+    pxml->stack_level++;
+
+    ws_writefd(pxml->pwsc,"<%s>",term);
+}
+
+/**
+ * end an xml section
+ *
+ * @param pxml xml struct we are working with
+ */
+void xml_pop(XMLSTRUCT *pxml) {
+    XMLSTACK *pstack;
+    
+    pstack=pxml->stack.next;
+    if(!pstack) {
+        DPRINTF(E_LOG,L_XML,"xml_pop: tried to pop an empty stack\n");
+        return;
+    }
+    
+    pxml->stack.next = pstack->next;
+    
+    ws_writefd(pxml->pwsc,"</%s>",pstack->tag);
+    free(pstack->tag);
+    free(pstack);
+    
+    pxml->stack_level--;
+}
+
+/**
+ * output a string
+ */
+void xml_output(XMLSTRUCT *pxml, char *section, char *fmt, ...) {
+    va_list ap;
+    char buf[256];
+    char *output;
+
+    va_start(ap, fmt);
+    vsnprintf(buf, sizeof(buf), fmt, ap);
+    va_end(ap);
+
+    output = xml_entity_encode(buf);
+    if(section) {
+        xml_push(pxml,section);
+    }
+    ws_writefd(pxml->pwsc,"%s",output);
+    free(output);
+    if(section) {
+        xml_pop(pxml);
+    }
+}
+
+/**
+ * clean up an xml struct
+ *
+ * @param pxml xml struct to clean up
+ */
+void xml_deinit(XMLSTRUCT *pxml) {
+    XMLSTACK *pstack;
+    
+    if(pxml->stack.next) {
+        DPRINTF(E_LOG,L_XML,"xml_deinit: entries still on stack (%s)\n",pxml->stack.next->tag);
+    }
+    
+    while((pstack=pxml->stack.next)) {
+        pxml->stack.next=pstack->next;
+        free(pstack->tag);
+        free(pstack);
+    }
+    free(pxml);
+}
 
 /**
  * main entrypoint for the xmlrpc functions.
@@ -66,39 +186,33 @@ void xml_get_stats(WS_CONNINFO *pwsc) {
     SCAN_STATUS *pss;
     WSTHREADENUM wste;
     
-
-    ws_addresponseheader(pwsc,"Content-Type","text/xml; charset=utf-8");
-    ws_writefd(pwsc,"HTTP/1.0 200 OK\r\n");
-    ws_emitheaders(pwsc);
-
-    ws_writefd(pwsc,"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>");
-    ws_writefd(pwsc,"<status>");
-
-    ws_writefd(pwsc,"<service_status>");
-    /* enumerate services? */
-    ws_writefd(pwsc,"</service_status>");
+    XMLSTRUCT *pxml;
     
-    ws_writefd(pwsc,"<thread_status>");
-    /* enumerate thread status */
+    pxml=xml_init(pwsc,1);
+    xml_push(pxml,"status");
+
+    xml_push(pxml,"service_status");
+    xml_pop(pxml); /* service_status */
+    
+    xml_push(pxml,"thread_status");
 
     pci = ws_thread_enum_first(config.server,&wste);
     while(pci) {
         pss = ws_get_local_storage(pci);
         if(pss) {
-            ws_writefd(pwsc,"<thread><id>%d</id><sourceip>%s</sourceip><action>%s</action></thread>",
-                       pss->thread,pss->host,pss->what);
+            xml_push(pxml,"thread");
+            xml_output(pxml,"id","%d",pss->thread);
+            xml_output(pxml,"sourceip","%s",pss->host);
+            xml_output(pxml,"action","%s",pss->what);
+            xml_pop(pxml); /* thread */
         }
         pci=ws_thread_enum_next(config.server,&wste);
     }
     
-    
-    ws_writefd(pwsc,"</thread_status>");
-
-    ws_writefd(pwsc,"<statistics>");
-    /* dump stats */
-    
-    ws_writefd(pwsc,"<stat name=\"uptime\">");
+    xml_pop(pxml); /* thread_status */
 
+    xml_push(pxml,"statistics");
+   
     r_secs=time(NULL)-config.stats.start_time;
 
     r_days=r_secs/(3600 * 24);
@@ -126,11 +240,14 @@ void xml_get_stats(WS_CONNINFO *pwsc) {
     sprintf((char*)&buf[strlen(buf)],"%d second%s ", r_secs,
 	    r_secs == 1 ? "" : "s");
     
-    ws_writefd(pwsc,"<name>Uptime</name>");    
-    ws_writefd(pwsc,"<value>%s</value>",buf);
-    ws_writefd(pwsc,"</stat>");
-    ws_writefd(pwsc,"</statistics>");
-    ws_writefd(pwsc,"</status>");
+    xml_push(pxml,"stat");
+    xml_output(pxml,"name","Uptime");
+    xml_output(pxml,"value","%s",buf);
+    xml_pop(pxml); /* stat */
+    xml_pop(pxml); /* statistics */
+    xml_pop(pxml); /* status */
+
+    xml_deinit(pxml);
     return;
 }