Memory-map the command-line file.

PiperOrigin-RevId: 833347912
Change-Id: I6051da61f1029cde8abc78637d38aeac18876bd2

Author: cpovirk

src/tools/singlejar/BUILD

@@ -515,6 +515,7 @@ cc_library(
     hdrs = ["token_stream.h"],
     deps = [
         ":diag",
+        ":mapped_file",
         "//src/main/cpp/util",
     ],
 )

src/tools/singlejar/token_stream.h

@@ -27,6 +27,7 @@
 
 #include "src/main/cpp/util/path_platform.h"
 #include "src/tools/singlejar/diag.h"
+#include "src/tools/singlejar/mapped_file.h"
 
 /*
  * Tokenize command line containing indirect command line arguments.
@@ -59,39 +60,26 @@ class ArgTokenStream {
   // Internal class to handle indirect command files.
   class FileTokenStream {
    public:
-    FileTokenStream(const char *filename) {
-#ifdef _WIN32
-      std::wstring wpath;
-      std::string error;
-      if (!blaze_util::AsAbsoluteWindowsPath(filename, &wpath, &error)) {
-        diag_err(1, "%s:%d: AsAbsoluteWindowsPath failed: %s", __FILE__,
-                 __LINE__, error.c_str());
-      }
-      fp_ = _wfopen(wpath.c_str(), L"r");
-#else
-      fp_ = fopen(filename, "r");
-#endif
-
-      if (!fp_) {
-        diag_err(1, "%s", filename);
+    FileTokenStream(const char* filename)
+        : next_ptr_(nullptr), end_ptr_(nullptr) {
+      if (!mapped_file_.Open(filename)) {
+        diag_err(1, "Cannot open param file: %s", filename);
       }
       filename_ = filename;
+      next_ptr_ = static_cast<const unsigned char*>(mapped_file_.start());
+      end_ptr_ = static_cast<const unsigned char*>(mapped_file_.end());
       next_char();
     }
 
-    ~FileTokenStream() { close(); }
+    ~FileTokenStream() = default;
 
     // Assign next token to TOKEN, return true on success, false on EOF.
     bool next_token(std::string *token) {
-      if (!fp_) {
-        return false;
-      }
       *token = "";
       while (current_char_ != EOF && isspace(current_char_)) {
         next_char();
       }
       if (current_char_ == EOF) {
-        close();
         return false;
       }
       for (;;) {
@@ -123,14 +111,6 @@ class ArgTokenStream {
     }
 
    private:
-    void close() {
-      if (fp_) {
-        fclose(fp_);
-        fp_ = nullptr;
-      }
-      filename_.clear();
-    }
-
     // Append the quoted string to the TOKEN. The quote character (which can be
     // single or double quote) is in the current character. Everything up to the
     // matching quote character is appended.
@@ -164,34 +144,41 @@ class ArgTokenStream {
     // Get the next character from the input stream. Skip backslash followed
     // by the newline.
     void next_char() {
-      if (feof(fp_)) {
-        current_char_ = EOF;
-        return;
-      }
-      current_char_ = getc(fp_);
-      // Eat "\\\n" sequence.
-      while (current_char_ == '\\') {
-        int c = getc(fp_);
-        if (c == '\n') {
-          current_char_ = getc(fp_);
-        } else {
-          if (c != EOF) {
-            ungetc(c, fp_);
-          }
-          break;
-        }
+      do {
+        current_char_ = raw_next();
+      } while (eat_line_continuation());
+    }
+
+    bool eat_line_continuation() {
+      if (current_char_ == '\\' && peek_raw_next() == '\n') {
+        next_ptr_++;
+        return true;
+      } else if (current_char_ == '\\' && peek_raw_next() == '\r' &&
+                 peek_raw_next(1) == '\n') {
+        next_ptr_ += 2;
+        return true;
       }
+      return false;
+    }
+
+    int raw_next() { return next_ptr_ < end_ptr_ ? *next_ptr_++ : EOF; }
+
+    int peek_raw_next(size_t offset = 0) {
+      return (next_ptr_ + offset) < end_ptr_ ? *(next_ptr_ + offset) : EOF;
     }
 
-    FILE *fp_;
+    MappedFile mapped_file_;
     std::string filename_;
+    const unsigned char* next_ptr_;
+    const unsigned char* end_ptr_;
     int current_char_;
   };
 
  public:
   // Constructor. Automatically reads the first token.
   ArgTokenStream(int argc, const char *const *argv)
       : argv_(argv), argv_end_(argv + argc) {
+    token_.reserve(1024);
     next();
   }
 

tools/jdk/BUILD.java_tools

@@ -566,6 +566,7 @@ cc_library(
     deps = [
         ":diag",
         ":filesystem",
+        ":mapped_file",
     ],
 )