diff --git a/similarity_search/include/read_data.h b/similarity_search/include/read_data.h
new file mode 100644
index 0000000..c360690
--- /dev/null
+++ b/similarity_search/include/read_data.h
@@ -0,0 +1,258 @@
+#ifndef READ_DATA_H
+#define READ_DATA_H
+
+#include <cmath>
+#include <string>
+#include <limits>
+#include <iomanip>
+#include <sstream>
+#include <cstdio>
+#include <vector>
+
+namespace similarity {
+
+using std::string;
+using std::vector;
+using std::stringstream;
+
+template <typename dist_t>
+struct SparseVectElem {  
+  uint32_t  id_;
+  dist_t    val_;
+  SparseVectElem(uint32_t id = 0, dist_t val = 0) : id_(id), val_(val) {}
+  bool operator<(const SparseVectElem<dist_t>& that) const {
+    return id_ < that.id_;
+  }
+  bool operator==(const SparseVectElem<dist_t>& that) const {
+    return id_ == that.id_ && val_ == that.val_;
+  }
+  bool operator!=(const SparseVectElem<dist_t>& that) const {
+    return !operator==(that);
+  }
+};
+
+template <typename dist_t>
+inline ostream& operator<<(ostream& out, SparseVectElem<dist_t> e) {
+  return out << "[" << e.id_ << ": " << e.val_ << "]";
+}
+
+inline int strtoi_wrapper(const char* ptr, char** endPtr) {
+  errno = 0;
+  long val = strtol(ptr, endPtr, 10);
+  if (errno == ERANGE){
+    return 0;
+  }
+  if (val < INT_MIN || val > INT_MAX) {
+    *endPtr = const_cast<char*>(ptr);
+    errno = ERANGE;
+    return 0;
+  }
+  return static_cast<int>(val);
+}
+
+template <typename T>
+inline bool ReadVecDataViaStream(string line, vector<T>& res) {
+  try {
+    res.clear();
+    ReplaceSomePunct(line); 
+
+    stringstream str(line);
+    str.exceptions(ios::badbit);
+
+    T val;
+    while (str >> val) {
+      res.push_back(val);
+    }
+  } catch (const exception& e) {
+    LOG(LIB_ERROR) << "Exception: " << e.what();
+    return false;
+  }
+  return true;
+}
+
+template <typename T>
+inline bool ReadVecDataEfficiently(string line, vector<T>& res);
+
+template <>
+inline bool ReadVecDataEfficiently<float>(string line, vector<float>& res) {
+  ReplaceSomePunct(line); 
+  const char *ptr = line.c_str();
+  char *endPtr = nullptr;
+
+  res.clear();
+  errno = 0;
+
+  for (float val = strtof(ptr, &endPtr);
+    ptr != endPtr;
+    val = strtof(ptr, &endPtr)) {
+    ptr = endPtr;
+    if (errno == ERANGE){
+      errno = 0;
+      return false;
+    }
+    res.push_back(val);
+  }
+
+  if (errno == ERANGE){
+    errno = 0;
+    return false;
+  }
+
+  return true;
+}
+
+template <>
+inline bool ReadVecDataEfficiently<double>(string line, vector<double>& res) {
+  ReplaceSomePunct(line); 
+  const char *ptr = line.c_str();
+  char *endPtr = nullptr;
+
+  res.clear();
+  errno = 0;
+
+  for (double val = strtod(ptr, &endPtr);
+    ptr != endPtr;
+    val = strtod(ptr, &endPtr)) {
+    ptr = endPtr;
+    if (errno == ERANGE){
+      errno = 0;
+      return false;
+    }
+    res.push_back(val);
+  }
+
+  if (errno == ERANGE){
+    errno = 0;
+    return false;
+  }
+
+  return true;
+}
+
+
+template <>
+inline bool ReadVecDataEfficiently<int>(string line, vector<int>& res) {
+  ReplaceSomePunct(line); 
+  const char *ptr = line.c_str();
+  char *endPtr = nullptr;
+
+  res.clear();
+  errno = 0;
+
+  for (int val = strtoi_wrapper(ptr, &endPtr);
+    ptr != endPtr;
+    val = strtoi_wrapper(ptr, &endPtr)) {
+    ptr = endPtr;
+    if (errno == ERANGE){
+      errno = 0;
+      return false;
+    }
+    res.push_back(val);
+  }
+
+  if (errno == ERANGE){
+    errno = 0;
+    return false;
+  }
+
+  return true;
+}
+
+
+template <typename T>
+inline bool ReadSparseVecDataViaStream(string line, vector<SparseVectElem<T>>& res) {
+  try {
+    ReplaceSomePunct(line); 
+    std::stringstream str(line);
+    str.exceptions(std::ios::badbit);
+
+    res.clear();
+
+    uint32_t id;
+    T        val;
+
+    while (str >> id && str >> val) {
+      res.push_back(SparseVectElem<T>(id, val));
+    }
+  } catch (const exception& e) {
+    LOG(LIB_ERROR) << "Exception: " << e.what();
+    return false;
+  }
+
+  return true;
+}
+
+template <typename T>
+inline bool ReadSparseVecDataEfficiently(string line, vector<SparseVectElem<T>>& res);
+
+template <>
+inline bool ReadSparseVecDataEfficiently<float>(string line, vector<SparseVectElem<float>>& res) {
+  ReplaceSomePunct(line); 
+  const char *ptr = line.c_str();
+  char *endPtr = nullptr;
+
+  float val; IdType id;
+
+  res.clear();
+  errno = 0;
+
+  while (true) {
+    if (endPtr != nullptr) ptr = endPtr;
+    id = strtoi_wrapper(ptr, &endPtr);
+    if (errno == ERANGE){
+      errno = 0;
+      return false;
+    }
+    if (ptr == endPtr) break;
+
+    ptr = endPtr;
+    val = strtof(ptr, &endPtr);
+    if (errno == ERANGE) {
+      errno = 0;
+      return false;
+    }
+    if (ptr == endPtr) return false;
+
+    res.push_back(SparseVectElem<float>(id, val));
+  };
+
+  return true;
+}
+
+template <>
+inline bool ReadSparseVecDataEfficiently<double>(string line, vector<SparseVectElem<double>>& res) {
+  ReplaceSomePunct(line); 
+  const char *ptr = line.c_str();
+  char *endPtr = nullptr;
+
+  double val; IdType id;
+
+  res.clear();
+  errno = 0;
+
+  while (true) {
+    if (endPtr != nullptr) ptr = endPtr;
+    id = strtoi_wrapper(ptr, &endPtr);
+    if (errno == ERANGE){
+      errno = 0;
+      return false;
+    }
+    if (ptr == endPtr) break;
+
+    ptr = endPtr;
+    val = strtod(ptr, &endPtr);
+    if (errno == ERANGE) {
+      errno = 0;
+      return false;
+    }
+    if (ptr == endPtr) return false;
+
+    res.push_back(SparseVectElem<double>(id, val));
+  };
+
+  return true;
+}
+
+}
+
+#endif
diff --git a/similarity_search/include/space/space_sparse_vector.h b/similarity_search/include/space/space_sparse_vector.h
index b426fd3..74d1fba 100644
--- a/similarity_search/include/space/space_sparse_vector.h
+++ b/similarity_search/include/space/space_sparse_vector.h
@@ -31,33 +31,13 @@
 #include "utils.h"
 #include "space.h"
 #include "distcomp.h"
+#include "read_data.h"
 
 namespace similarity {
 
 using std::vector;
 using std::fill;
 
-template <typename dist_t>
-struct SparseVectElem {  
-  uint32_t  id_;
-  dist_t    val_;
-  SparseVectElem(uint32_t id = 0, dist_t val = 0) : id_(id), val_(val) {}
-  bool operator<(const SparseVectElem<dist_t>& that) const {
-    return id_ < that.id_;
-  }
-  bool operator==(const SparseVectElem<dist_t>& that) const {
-    return id_ == that.id_ && val_ == that.val_;
-  }
-  bool operator!=(const SparseVectElem<dist_t>& that) const {
-    return !operator==(that);
-  }
-};
-
-template <typename dist_t>
-ostream& operator<<(ostream& out, SparseVectElem<dist_t> e) {
-  return out << "[" << e.id_ << ": " << e.val_ << "]";
-}
-
 /* 
  * The maximum number of sparse elements that will be kept on the stack
  * by the function ComputeDistanceHelper. 
diff --git a/similarity_search/src/space/space_sparse_vector.cc b/similarity_search/src/space/space_sparse_vector.cc
index 077a70f..2c18a3f 100644
--- a/similarity_search/src/space/space_sparse_vector.cc
+++ b/similarity_search/src/space/space_sparse_vector.cc
@@ -27,30 +27,30 @@
 #include "logging.h"
 #include "distcomp.h"
 #include "experimentconf.h"
+#include "read_data.h"
 
 namespace similarity {
 
 using namespace std;
 
 template <typename dist_t>
-void SpaceSparseVector<dist_t>::ReadSparseVec(std::string line, size_t line_num, LabelType& label, vector<ElemType>& v) const
+void SpaceSparseVector<dist_t>::ReadSparseVec(string line, size_t line_num, LabelType& label, vector<ElemType>& v) const
 {
   v.clear();
 
   label = Object::extractLabel(line);
 
-  ReplaceSomePunct(line); 
-  std::stringstream str(line);
-
-  str.exceptions(std::ios::badbit);
-
-  uint32_t id;
-  dist_t   val;
+#if 0
+  if (!ReadSparseVecDataViaStream(line, v)) {
+#else
+  if (!ReadSparseVecDataEfficiently(line, v)) {
+#endif
+    PREPARE_RUNTIME_ERR(err) << "Failed to parse the line # " << line_num << ": '" << line << "'" << std::endl;
+    LOG(LIB_ERROR) << err.stream().str();
+    THROW_RUNTIME_ERR(err);
+  }
 
   try {
-    while (str >> id && str >> val) {
-      v.push_back(ElemType(id, val));
-    }
     sort(v.begin(), v.end());
 
     for (unsigned i = 1; i < v.size(); ++i) {
diff --git a/similarity_search/src/space/space_vector.cc b/similarity_search/src/space/space_vector.cc
index 7dd93e1..743ff81 100644
--- a/similarity_search/src/space/space_vector.cc
+++ b/similarity_search/src/space/space_vector.cc
@@ -22,6 +22,8 @@
 #include <memory>
 #include <iomanip>
 #include <limits>
+#include <cstdio>
+#include <cstdint>
 
 #include "object.h"
 #include "utils.h"
@@ -29,6 +31,7 @@
 #include "distcomp.h"
 #include "experimentconf.h"
 #include "space/space_vector.h"
+#include "read_data.h"
 
 namespace similarity {
 
@@ -126,21 +129,14 @@ void VectorSpace<dist_t>::ReadVec(string line, LabelType& label, vector<dist_t>&
 
   label = Object::extractLabel(line);
 
-  ReplaceSomePunct(line); 
-  stringstream str(line);
-
-  str.exceptions(ios::badbit);
-
-  dist_t val;
-
-
-  try {
-    while (str >> val) {
-      v.push_back(val);
-    }
-  } catch (const exception &e) {
-    LOG(LIB_ERROR) << "Exception: " << e.what();
-    LOG(LIB_FATAL) << "Failed to parse the line: '" << line << "'";
+#if 0
+  if (!ReadVecDataViaStream(line, v)) {
+#else
+  if (!ReadVecDataEfficiently(line, v)) {
+#endif
+    PREPARE_RUNTIME_ERR(err) << "Failed to parse the line: '" << line << "'";
+    LOG(LIB_ERROR) << err.stream().str();
+    THROW_RUNTIME_ERR(err);
   }
 }