1 files changed, 41 insertions, 0 deletions
diff --git a/tensorflow/core/graph/tensor_id.cc b/tensorflow/core/graph/tensor_id.cc
new file mode 100644
index 0000000000..f789110ff3
--- /dev/null
+++ b/tensorflow/core/graph/tensor_id.cc
@@ -0,0 +1,41 @@
+#include "tensorflow/core/graph/tensor_id.h"
+
+#include <string>
+
+#include "tensorflow/core/lib/core/stringpiece.h"
+
+namespace tensorflow {
+
+TensorId ParseTensorName(const string& name) {
+  return ParseTensorName(StringPiece(name.data(), name.size()));
+}
+
+TensorId ParseTensorName(StringPiece name) {
+  // Parse either a name, or a name:digits.  To do so, we go backwards
+  // from the end of the string, skipping over a run of digits.  If
+  // we hit a ':' character, then we know we are in the 'name:digits'
+  // regime.  Otherwise, the output index is implicitly 0, and the whole
+  // name string forms the first part of the tensor name.
+  //
+  // Equivalent to matching with this regexp: ([^:]+):(\\d+)
+  const char* base = name.data();
+  const char* p = base + name.size() - 1;
+  int index = 0;
+  int mul = 1;
+  while (p > base && (*p >= '0' && *p <= '9')) {
+    index += ((*p - '0') * mul);
+    mul *= 10;
+    p--;
+  }
+  TensorId id;
+  if (p > base && *p == ':' && mul > 1) {
+    id.first = StringPiece(base, p - base);
+    id.second = index;
+  } else {
+    id.first = name;
+    id.second = 0;
+  }
+  return id;
+}
+
+}  // namespace tensorflow