changeset 593:70acfcb5010a

Remove mmap() from l2norm.cpp

We use instead a similarly bad method for dealing with l2norming when
there's already data in the database: malloc() a buffer the size of the
data.  This will likely fail in even more cases than the previous
mmap()-the-buffer strategy.

--- a/l2norm.cpp	Tue Aug 11 21:42:29 2009 +0000
+++ b/l2norm.cpp	Tue Aug 11 21:42:34 2009 +0000
@@ -4,32 +4,37 @@
 #include "audioDB-internals.h"
 
 static int audiodb_l2norm_existing(adb_t *adb) {
-  double *data_buffer, *l2norm_buffer;
-  adb_header_t *header = adb->header;
-  size_t data_buffer_size = align_page_up(header->length);
-  size_t nvectors = header->length / (sizeof(double) * header->dim);
-  /* FIXME: this map of the vector data will lose if we ever turn the
-   * l2norm flag on when we have already inserted a large number of
-   * vectors, as the mmap() will fail.  "Don't do that, then" is one
-   * possible answer. */
-  mmap_or_goto_error(double *, data_buffer, header->dataOffset, data_buffer_size);
+  double *data_buffer = 0, *l2norm_buffer = 0;
+  size_t data_buffer_size = align_page_up(adb->header->length);
+  size_t nvectors = adb->header->length / (sizeof(double) * adb->header->dim);
+  /* FIXME: this allocation of the vector data buffer will lose if we
+   * ever turn the l2norm flag on when we have already inserted a
+   * large number of vectors, as the malloc() will fail.  "Don't do
+   * that, then" is one possible answer. */
+  data_buffer = (double *) malloc(data_buffer_size);
+  if (!data_buffer) {
+    goto error;
+  }
+  lseek_set_or_goto_error(adb->fd, adb->header->dataOffset);
+  read_or_goto_error(adb->fd, data_buffer, data_buffer_size);
+
   l2norm_buffer = (double *) malloc(nvectors * sizeof(double));
   if(!l2norm_buffer) {
     goto error;
   }
-  audiodb_l2norm_buffer(data_buffer, header->dim, nvectors, l2norm_buffer);
-  if(lseek(adb->fd, adb->header->l2normTableOffset, SEEK_SET) == (off_t) -1) {
-    goto error;
-  }
+  audiodb_l2norm_buffer(data_buffer, adb->header->dim, nvectors, l2norm_buffer);
+  lseek_set_or_goto_error(adb->fd, adb->header->l2normTableOffset);
   write_or_goto_error(adb->fd, l2norm_buffer, nvectors * sizeof(double));
 
-  munmap(data_buffer, data_buffer_size);
   free(l2norm_buffer);
+  free(data_buffer);
 
   return 0;
 
  error:
-  maybe_munmap(data_buffer, data_buffer_size);
+  if(data_buffer) {
+    free(data_buffer);
+  }
   if(l2norm_buffer) {
     free(l2norm_buffer);
   }
@@ -37,16 +42,16 @@
 }
 
 int audiodb_l2norm(adb_t *adb) {
-  adb_header_t *header = adb->header;
   if(!(adb->flags & O_RDWR)) {
     return 1;
   }
-  if(header->flags & ADB_HEADER_FLAG_L2NORM) {
+  if(adb->header->flags & ADB_HEADER_FLAG_L2NORM) {
     /* non-error code for forthcoming backwards-compatibility
      * reasons */
     return 0;
   }
-  if((!(header->flags & ADB_HEADER_FLAG_REFERENCES)) && (header->length > 0)) {
+  if((!(adb->header->flags & ADB_HEADER_FLAG_REFERENCES)) && 
+     (adb->header->length > 0)) {
     if(audiodb_l2norm_existing(adb)) {
       goto error;
     }