1 files changed, 130 insertions, 0 deletions
diff --git a/mteval/ns_ext.cc b/mteval/ns_ext.cc
new file mode 100644
index 00000000..956708af
--- /dev/null
+++ b/mteval/ns_ext.cc
@@ -0,0 +1,130 @@
+#include "ns_ext.h"
+
+#include <cstdio> // popen
+#include <cstdlib>
+#include <cstring>
+#include <unistd.h>
+#include <sstream>
+#include <iostream>
+#include <cassert>
+
+#include "stringlib.h"
+#include "tdict.h"
+
+using namespace std;
+
+struct NScoreServer {
+  NScoreServer(const std::string& cmd);
+  ~NScoreServer();
+
+  float ComputeScore(const std::vector<float>& fields);
+  void Evaluate(const std::vector<std::vector<WordID> >& refs, const std::vector<WordID>& hyp, std::vector<float>* fields);
+
+ private:
+  void RequestResponse(const std::string& request, std::string* response);
+  int p2c[2];
+  int c2p[2];
+};
+
+NScoreServer::NScoreServer(const string& cmd) {
+  cerr << "Invoking " << cmd << " ..." << endl;
+  if (pipe(p2c) < 0) { perror("pipe"); exit(1); }
+  if (pipe(c2p) < 0) { perror("pipe"); exit(1); }
+  pid_t cpid = fork();
+  if (cpid < 0) { perror("fork"); exit(1); }
+  if (cpid == 0) {  // child
+    close(p2c[1]);
+    close(c2p[0]);
+    dup2(p2c[0], 0);
+    close(p2c[0]);
+    dup2(c2p[1], 1);
+    close(c2p[1]);
+    cerr << "Exec'ing from child " << cmd << endl;
+    vector<string> vargs;
+    SplitOnWhitespace(cmd, &vargs);
+    const char** cargv = static_cast<const char**>(malloc(sizeof(const char*) * vargs.size()));
+    for (unsigned i = 1; i < vargs.size(); ++i) cargv[i-1] = vargs[i].c_str();
+    cargv[vargs.size() - 1] = NULL;
+    execvp(vargs[0].c_str(), (char* const*)cargv);
+  } else { // parent
+    close(c2p[1]);
+    close(p2c[0]);
+  }
+  string dummy;
+  RequestResponse("SCORE ||| Reference initialization string . ||| Testing initialization string .", &dummy);
+  assert(dummy.size() > 0);
+  cerr << "Connection established.\n";
+}
+
+NScoreServer::~NScoreServer() {
+  // TODO close stuff, join stuff
+}
+
+float NScoreServer::ComputeScore(const vector<float>& fields) {
+  ostringstream os;
+  os << "EVAL |||";
+  for (unsigned i = 0; i < fields.size(); ++i)
+    os << ' ' << fields[i];
+  string sres;
+  RequestResponse(os.str(), &sres);
+  return strtod(sres.c_str(), NULL);
+}
+
+void NScoreServer::Evaluate(const vector<vector<WordID> >& refs, const vector<WordID>& hyp, vector<float>* fields) {
+  ostringstream os;
+  os << "SCORE";
+  for (unsigned i = 0; i < refs.size(); ++i) {
+    os << " |||";
+    for (unsigned j = 0; j < refs[i].size(); ++j) {
+      os << ' ' << TD::Convert(refs[i][j]);
+    }
+  }
+  os << " |||";
+  for (unsigned i = 0; i < hyp.size(); ++i) {
+    os << ' ' << TD::Convert(hyp[i]);
+  }
+  string sres;
+  RequestResponse(os.str(), &sres);
+  istringstream is(sres);
+  float val;
+  fields->clear();
+  while(is >> val)
+    fields->push_back(val);
+}
+
+#define MAX_BUF 16000
+
+void NScoreServer::RequestResponse(const string& request, string* response) {
+//  cerr << "@SERVER: " << request << endl;
+  string x = request + "\n";
+  write(p2c[1], x.c_str(), x.size());
+  char buf[MAX_BUF];
+  size_t n = read(c2p[0], buf, MAX_BUF);
+  while (n < MAX_BUF && buf[n-1] != '\n')
+    n += read(c2p[0], &buf[n], MAX_BUF - n);
+
+  buf[n-1] = 0;
+  if (n < 2) {
+    cerr << "Malformed response: " << buf << endl;
+  }
+  *response = Trim(buf, " \t\n");
+//  cerr << "@RESPONSE: '" << *response << "'\n";
+}
+
+void ExternalMetric::ComputeSufficientStatistics(const std::vector<WordID>& hyp,
+                                           const std::vector<std::vector<WordID> >& refs,
+                                           SufficientStats* out) const {
+  eval_server->Evaluate(refs, hyp, &out->fields);
+}
+
+float ExternalMetric::ComputeScore(const SufficientStats& stats) const {
+  eval_server->ComputeScore(stats.fields);
+}
+
+ExternalMetric::ExternalMetric(const string& metric_name, const std::string& command) :
+    EvaluationMetric(metric_name),
+    eval_server(new NScoreServer(command)) {}
+
+ExternalMetric::~ExternalMetric() {
+  delete eval_server;
+}