1 files changed, 106 insertions, 0 deletions
diff --git a/src/parser/memory_mapped_input_buffer.cpp b/src/parser/memory_mapped_input_buffer.cpp
new file mode 100644
index 000000000..6618ecebc
--- /dev/null
+++ b/src/parser/memory_mapped_input_buffer.cpp
@@ -0,0 +1,106 @@
+/*
+ * memory_mapped_input_buffer.cpp
+ *
+ *  Created on: Mar 3, 2010
+ *      Author: chris
+ */
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdint.h>
+
+#include <sys/errno.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <antlr3input.h>
+
+#include "memory_mapped_input_buffer.h"
+#include "util/Assert.h"
+#include "util/exception.h"
+
+namespace CVC4 {
+namespace parser {
+
+extern "C" {
+
+static ANTLR3_UINT32
+MemoryMapFile(pANTLR3_INPUT_STREAM input, const std::string& filename);
+
+void
+UnmapFile(pANTLR3_INPUT_STREAM input);
+
+pANTLR3_INPUT_STREAM MemoryMappedInputBufferNew(const std::string& filename) {
+  // Pointer to the input stream we are going to create
+  //
+  pANTLR3_INPUT_STREAM input;
+  ANTLR3_UINT32 status;
+
+  // Allocate memory for the input stream structure
+  //
+  input = (pANTLR3_INPUT_STREAM) ANTLR3_CALLOC(1, sizeof(ANTLR3_INPUT_STREAM));
+
+  if(input == NULL) {
+    return NULL;
+  }
+
+  // Structure was allocated correctly, now we can read the file.
+  //
+  status = MemoryMapFile(input, filename);
+
+  // Call the common 8 bit ASCII input stream handler
+  // Initializer type thingy doobry function.
+  //
+  antlr3AsciiSetupStream(input, ANTLR3_CHARSTREAM);
+
+  // Now we can set up the file name
+  //
+  input->istream->streamName
+      = input->strFactory->newStr(input->strFactory,
+                                  (uint8_t*) filename.c_str());
+  input->fileName = input->istream->streamName;
+  input->free = UnmapFile;
+
+  if(status != ANTLR3_SUCCESS) {
+    input->close(input);
+    return NULL;
+  }
+
+  return input;
+}
+
+static ANTLR3_UINT32 MemoryMapFile(pANTLR3_INPUT_STREAM input,
+                                   const std::string& filename) {
+  errno = 0;
+  struct stat st;
+  if(stat(filename.c_str(), &st) == -1) {
+    return ANTLR3_ERR_NOFILE;
+  }
+
+  input->sizeBuf = st.st_size;
+
+  int fd = open(filename.c_str(), O_RDONLY);
+  if(fd == -1) {
+    return ANTLR3_ERR_NOFILE;
+  }
+
+  input->data = mmap(0, input->sizeBuf, PROT_READ, MAP_FILE | MAP_PRIVATE, fd,
+                     0);
+  errno = 0;
+  if(intptr_t(input->data) == -1) {
+    return ANTLR3_ERR_NOMEM;
+  }
+
+  return ANTLR3_SUCCESS;
+}
+
+/* This is a bit shady. antlr3AsciiSetupStream has free and close as aliases.
+ * We need to unmap the file somewhere, so we install this function as free and
+ * call the default version of close to de-allocate everything else. */
+void UnmapFile(pANTLR3_INPUT_STREAM input) {
+  munmap((void*) input->data, input->sizeBuf);
+  input->close(input);
+}
+
+}
+}
+}