added ladspa, doesn't have checks yet though

Original commit message from CVS:
added ladspa, doesn't have checks yet though

1 files changed, 186 insertions, 0 deletions

diff --git a/ext/ladspa/load.c b/ext/ladspa/load.c
new file mode 100644
index 00000000..148f98fb
--- /dev/null
+++ b/ext/ladspa/load.c
@@ -0,0 +1,186 @@
+/* load.c
+
+   Free software by Richard W.E. Furse. Do with as you will. No
+   warranty. */
+
+/*****************************************************************************/
+
+#include <dlfcn.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/*****************************************************************************/
+
+#include "ladspa.h"
+#include "utils.h"
+
+/*****************************************************************************/
+
+/* This function provides a wrapping of dlopen(). When the filename is
+   not an absolute path (i.e. does not begin with / character), this
+   routine will search the LADSPA_PATH for the file. */
+static void *
+dlopenLADSPA(const char * pcFilename, int iFlag) {
+
+  char * pcBuffer;
+  const char * pcEnd;
+  const char * pcLADSPAPath;
+  const char * pcStart;
+  int iEndsInSO;
+  int iNeedSlash;
+  size_t iFilenameLength;
+  void * pvResult;
+
+  iFilenameLength = strlen(pcFilename);
+  pvResult = NULL;
+
+  if (pcFilename[0] == '/') {
+
+    /* The filename is absolute. Assume the user knows what he/she is
+       doing and simply dlopen() it. */
+
+    pvResult = dlopen(pcFilename, iFlag);
+    if (pvResult != NULL)
+      return pvResult;
+
+  }
+  else {
+
+    /* If the filename is not absolute then we wish to check along the
+       LADSPA_PATH path to see if we can find the file there. We do
+       NOT call dlopen() directly as this would find plugins on the
+       LD_LIBRARY_PATH, whereas the LADSPA_PATH is the correct place
+       to search. */
+
+    pcLADSPAPath = getenv("LADSPA_PATH");
+    
+    if (pcLADSPAPath) {
+
+      pcStart = pcLADSPAPath;
+      while (*pcStart != '\0') {
+	pcEnd = pcStart;
+	while (*pcEnd != ':' && *pcEnd != '\0')
+	  pcEnd++;
+	
+	pcBuffer = malloc(iFilenameLength + 2 + (pcEnd - pcStart));
+	if (pcEnd > pcStart)
+	  strncpy(pcBuffer, pcStart, pcEnd - pcStart);
+	iNeedSlash = 0;
+	if (pcEnd > pcStart)
+	  if (*(pcEnd - 1) != '/') {
+	    iNeedSlash = 1;
+	    pcBuffer[pcEnd - pcStart] = '/';
+	  }
+	strcpy(pcBuffer + iNeedSlash + (pcEnd - pcStart), pcFilename);
+	
+	pvResult = dlopen(pcBuffer, iFlag);
+	
+	free (pcBuffer);
+	if (pvResult != NULL)
+	  return pvResult;
+	
+	pcStart = pcEnd;
+	if (*pcStart == ':')
+	  pcStart++;
+      }
+    }
+  }
+
+  /* As a last ditch effort, check if filename does not end with
+     ".so". In this case, add this suffix and recurse. */
+  iEndsInSO = 0;
+  if (iFilenameLength > 3)
+    iEndsInSO = (strcmp(pcFilename + iFilenameLength - 3, ".so") == 0);
+  if (!iEndsInSO) {
+    pcBuffer = malloc(iFilenameLength + 4);
+    strcpy(pcBuffer, pcFilename);
+    strcat(pcBuffer, ".so");
+    pvResult = dlopenLADSPA(pcBuffer, iFlag);
+    free(pcBuffer);
+  }
+
+  if (pvResult != NULL)
+    return pvResult;
+
+  /* If nothing has worked, then at least we can make sure we set the
+     correct error message - and this should correspond to a call to
+     dlopen() with the actual filename requested. The dlopen() manual
+     page does not specify whether the first or last error message
+     will be kept when multiple calls are made to dlopen(). We've
+     covered the former case - now we can handle the latter by calling
+     dlopen() again here. */
+  return dlopen(pcFilename, iFlag);
+}
+
+/*****************************************************************************/
+
+void *
+loadLADSPAPluginLibrary(const char * pcPluginFilename) {
+
+  void * pvPluginHandle;
+
+  pvPluginHandle = dlopenLADSPA(pcPluginFilename, RTLD_NOW);
+  if (!pvPluginHandle) {
+    fprintf(stderr, 
+	    "Failed to load plugin \"%s\": %s\n", 
+	    pcPluginFilename,
+	    dlerror());
+    exit(1);
+  }
+
+  return pvPluginHandle;
+}
+
+/*****************************************************************************/
+
+void 
+unloadLADSPAPluginLibrary(void * pvLADSPAPluginLibrary) {
+  dlclose(pvLADSPAPluginLibrary);
+}
+
+/*****************************************************************************/
+
+const LADSPA_Descriptor *
+findLADSPAPluginDescriptor(void * pvLADSPAPluginLibrary,
+			   const char * pcPluginLibraryFilename,
+			   const char * pcPluginLabel) {
+
+  const LADSPA_Descriptor * psDescriptor;
+  LADSPA_Descriptor_Function pfDescriptorFunction;
+  unsigned long lPluginIndex;
+
+  dlerror();
+  pfDescriptorFunction 
+    = (LADSPA_Descriptor_Function)dlsym(pvLADSPAPluginLibrary,
+					"ladspa_descriptor");
+  if (!pfDescriptorFunction) {
+    const char * pcError = dlerror();
+    if (pcError) {
+      fprintf(stderr,
+	      "Unable to find ladspa_descriptor() function in plugin "
+	      "library file \"%s\": %s.\n"
+	      "Are you sure this is a LADSPA plugin file?\n", 
+	      pcPluginLibraryFilename,
+	      pcError);
+      exit(1);
+    }
+  }
+
+  for (lPluginIndex = 0;; lPluginIndex++) {
+    psDescriptor = pfDescriptorFunction(lPluginIndex);
+    if (psDescriptor == NULL) {
+      fprintf(stderr,
+	      "Unable to find label \"%s\" in plugin library file \"%s\".\n",
+	      pcPluginLabel,
+	      pcPluginLibraryFilename);
+      exit(1);      
+    }
+    if (strcmp(psDescriptor->Label, pcPluginLabel) == 0)
+      return psDescriptor;
+  }
+}
+
+/*****************************************************************************/
+
+/* EOF */