fixes rexyai#151

hafen · Jun 10, 2020 · 7110854 · 7110854
1 parent 77e86aa
commit 7110854
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Showing 5 changed files with 31 additions and 2 deletions.
diff --git a/R/RcppExports.R b/R/RcppExports.R
@@ -25,6 +25,10 @@ cpp_parse_multipart_body <- function(body, boundary) {
     .Call(`_RestRserve_cpp_parse_multipart_body`, body, boundary)
 }
 
+raw_slice <- function(x, offset, size) {
+    .Call(`_RestRserve_raw_slice`, x, offset, size)
+}
+
 cpp_url_decode <- function(x) {
     .Call(`_RestRserve_cpp_url_decode`, x)
 }

diff --git a/R/Request.R b/R/Request.R
@@ -208,8 +208,9 @@ Request = R6::R6Class(
       if (is.null(self$files[[name]]) || !is.raw(self$body)) {
         return(NULL)
       }
-      idx = seq_len(self$files[[name]]$length) + self$files[[name]]$offset - 1L
-      res = self$body[idx]
+      # see https://github.com/rexyai/RestRserve/issues/151
+      # https://stackoverflow.com/questions/56614592/faster-way-to-slice-a-raw-vector
+      res = raw_slice(self$body, self$files[[name]]$offset, self$files[[name]]$length)
       attr(res, "filname") = self$files[[name]]$filename
       attr(res, "content-type") = self$files[[name]]$content_type
       return(res)

diff --git a/src/RcppExports.cpp b/src/RcppExports.cpp
@@ -66,6 +66,18 @@ BEGIN_RCPP
     return rcpp_result_gen;
 END_RCPP
 }
+// raw_slice
+Rcpp::RawVector raw_slice(const Rcpp::RawVector& x, const R_xlen_t offset, const R_xlen_t size);
+RcppExport SEXP _RestRserve_raw_slice(SEXP xSEXP, SEXP offsetSEXP, SEXP sizeSEXP) {
+BEGIN_RCPP
+    Rcpp::RObject rcpp_result_gen;
+    Rcpp::traits::input_parameter< const Rcpp::RawVector& >::type x(xSEXP);
+    Rcpp::traits::input_parameter< const R_xlen_t >::type offset(offsetSEXP);
+    Rcpp::traits::input_parameter< const R_xlen_t >::type size(sizeSEXP);
+    rcpp_result_gen = Rcpp::wrap(raw_slice(x, offset, size));
+    return rcpp_result_gen;
+END_RCPP
+}
 // cpp_url_decode
 Rcpp::CharacterVector cpp_url_decode(Rcpp::CharacterVector x);
 RcppExport SEXP _RestRserve_cpp_url_decode(SEXP xSEXP) {
@@ -96,6 +108,7 @@ static const R_CallMethodDef CallEntries[] = {
     {"_RestRserve_cpp_parse_headers", (DL_FUNC) &_RestRserve_cpp_parse_headers, 1},
     {"_RestRserve_cpp_parse_multipart_boundary", (DL_FUNC) &_RestRserve_cpp_parse_multipart_boundary, 1},
     {"_RestRserve_cpp_parse_multipart_body", (DL_FUNC) &_RestRserve_cpp_parse_multipart_body, 2},
+    {"_RestRserve_raw_slice", (DL_FUNC) &_RestRserve_raw_slice, 3},
     {"_RestRserve_cpp_url_decode", (DL_FUNC) &_RestRserve_cpp_url_decode, 1},
     {"_RestRserve_cpp_url_encode", (DL_FUNC) &_RestRserve_cpp_url_encode, 1},
     {NULL, NULL, 0}

diff --git a/src/parse_multipart.cpp b/src/parse_multipart.cpp
@@ -163,3 +163,13 @@ Rcpp::List cpp_parse_multipart_body(Rcpp::RawVector body, const char* boundary)
   );
   return res;
 }
+
+// see https://github.com/rexyai/RestRserve/issues/151
+// https://stackoverflow.com/questions/56614592/faster-way-to-slice-a-raw-vector
+
+// [[Rcpp::export(rng=false)]]
+Rcpp::RawVector raw_slice(const Rcpp::RawVector &x, const R_xlen_t offset, const R_xlen_t size) {
+  Rcpp::RawVector result = Rcpp::no_init(size);
+  memcpy ( &result[0], &x[offset - 1], size );
+  return result;
+}
diff --git a/src/utils.h b/src/utils.h
@@ -20,5 +20,6 @@ std::string str_join(const std::vector<T>&, const char*);
 std::string str_join(Rcpp::CharacterVector, const char*);
 template<typename T>
 Rcpp::Environment map_to_env(const std::unordered_map<std::string,T>&);
+Rcpp::RawVector raw_slice(const Rcpp::RawVector &x, const R_xlen_t offset, const R_xlen_t size);
 
 #endif