Add support for manifest_serializer long lines mode

5 files changed, 54 insertions, 13 deletions

diff --git a/libbutl/manifest-rewriter.cxx b/libbutl/manifest-rewriter.cxx
index 2be53f1..e5b4eae 100644
--- a/libbutl/manifest-rewriter.cxx
+++ b/libbutl/manifest-rewriter.cxx
@@ -41,8 +41,9 @@ using namespace std;
 namespace butl
 {
   manifest_rewriter::
-  manifest_rewriter (path p)
+  manifest_rewriter (path p, bool long_lines)
       : path_ (move (p)),
+        long_lines_ (long_lines),
         fd_ (fdopen (path_,
                      fdopen_mode::in  |
                      fdopen_mode::out |
@@ -99,7 +100,7 @@ namespace butl
     {
       os << ' ';
 
-      manifest_serializer s (os, path_.string ());
+      manifest_serializer s (os, path_.string (), long_lines_);
 
       s.write_value (nv.value,
                      static_cast<size_t> (nv.colon_pos - nv.start_pos + 2));
@@ -127,7 +128,7 @@ namespace butl
     ofdstream os (move (fd_));
     os << '\n';
 
-    manifest_serializer s (os, path_.string ());
+    manifest_serializer s (os, path_.string (), long_lines_);
     s.write_name (nv.name);
 
     os << ':';
diff --git a/libbutl/manifest-rewriter.mxx b/libbutl/manifest-rewriter.mxx
index 6cba682..8ad22b3 100644
--- a/libbutl/manifest-rewriter.mxx
+++ b/libbutl/manifest-rewriter.mxx
@@ -50,7 +50,10 @@ LIBBUTL_MODEXPORT namespace butl
   class LIBBUTL_SYMEXPORT manifest_rewriter
   {
   public:
-    manifest_rewriter (path);
+    // Unless long_lines is true, break lines in values (see
+    // manifest_serializer for details).
+    //
+    manifest_rewriter (path, bool long_lines = false);
 
     // Replace the existing value at the specified position (specifically,
     // between colon_pos and end_pos) with the specified new value. The new
@@ -70,6 +73,7 @@ LIBBUTL_MODEXPORT namespace butl
 
   private:
     path path_;
+    bool long_lines_;
     auto_fd fd_;
   };
 }
diff --git a/libbutl/manifest-serializer.cxx b/libbutl/manifest-serializer.cxx
index 2098551..059c374 100644
--- a/libbutl/manifest-serializer.cxx
+++ b/libbutl/manifest-serializer.cxx
@@ -182,7 +182,6 @@ namespace butl
     {
       char pc (c);
       c = *s;
-      bool br (false); // Break the line.
 
       // Note that even the "hard" break (see below) is not that hard when it
       // comes to breaking the line right after the backslash. Doing so would
@@ -190,8 +189,10 @@ namespace butl
       // backslash would be escaped. So we delay breaking till the next
       // non-backslash character.
       //
-      if (pc != '\\')
+      if (pc != '\\' && !long_lines_)
       {
+        bool br (false); // Break the line.
+
         // If this is a whitespace, see if it's a good place to break the
         // line.
         //
@@ -238,7 +239,7 @@ namespace butl
       os_ << c;
     }
 
-    // What comes next is always a newline. I the last character that
+    // What comes next is always a newline. If the last character that
     // we have written is a backslash, escape it.
     //
     if (c == '\\')
@@ -261,6 +262,11 @@ namespace butl
     // - value contains newlines
     // - value contains leading/trailing whitespaces
     //
+    // Should we use the multi-line mode for large column offsets if the long
+    // lines flag is set? Probably yes, as this improves the manifest
+    // readability, still allowing the user to easily copy the value which
+    // seems to be the main reason for using the flag.
+    //
     if (cl > 39 || nl () != string::npos ||
         v.front () == ' ' || v.front () == '\t' ||
         v.back () == ' ' || v.back () == '\t')
diff --git a/libbutl/manifest-serializer.mxx b/libbutl/manifest-serializer.mxx
index 7df78d5..1b3ace8 100644
--- a/libbutl/manifest-serializer.mxx
+++ b/libbutl/manifest-serializer.mxx
@@ -56,10 +56,19 @@ LIBBUTL_MODEXPORT namespace butl
     using filter_function = bool (const std::string& name,
                                   const std::string& value);
 
+    // Unless long_lines is true, break lines in values (including multi-line)
+    // so that their length does not exceed 78 characters (including '\n').
+    //
     manifest_serializer (std::ostream& os,
                          const std::string& name,
+                         bool long_lines = false,
                          std::function<filter_function> filter = {})
-        : os_ (os), name_ (name), filter_ (std::move (filter)) {}
+      : os_ (os),
+        name_ (name),
+        long_lines_ (long_lines),
+        filter_ (std::move (filter))
+    {
+    }
 
     const std::string&
     name () const {return name_;}
@@ -124,6 +133,7 @@ LIBBUTL_MODEXPORT namespace butl
   private:
     std::ostream& os_;
     const std::string name_;
+    bool long_lines_;
     const std::function<filter_function> filter_;
   };
 }
diff --git a/tests/manifest-serializer/driver.cxx b/tests/manifest-serializer/driver.cxx
index d6e538d..4cddb57 100644
--- a/tests/manifest-serializer/driver.cxx
+++ b/tests/manifest-serializer/driver.cxx
@@ -32,6 +32,7 @@ using pairs = vector<pair<string, string>>;
 static bool
 test (const pairs& manifest,
       const string& expected,
+      bool long_lines = false,
       manifest_serializer::filter_function f = {});
 
 static bool
@@ -178,7 +179,6 @@ main ()
   assert (test ({{"","1"},{"a",l4},{"",""},{"",""}}, ": 1\na: " + e4 + "\n"));
   assert (test ({{"","1"},{"a",l5},{"",""},{"",""}}, ": 1\na: " + e5 + "\n"));
 
-
   // Multi-line value.
   //
   string n ("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
@@ -199,6 +199,20 @@ main ()
   assert (test ({{"","1"},{"a"," x "},{"",""},{"",""}},
                 ": 1\na: \\\n x \n\\\n"));
 
+  // The long lines mode.
+  //
+  assert (test ({{"","1"},{"a",l1},{"",""},{"",""}},
+                ": 1\na: " + l1 + "\n",
+                true /* long_lines */));
+
+  assert (test ({{"","1"},{"a", " abc\n" + l1 + "\ndef"},{"",""},{"",""}},
+                ": 1\na: \\\n abc\n" + l1 + "\ndef\n\\\n",
+                true /* long_lines */));
+
+  assert (test ({{"","1"},{n,l1},{"",""},{"",""}},
+                ": 1\n" + n + ": \\\n" + l1 + "\n\\\n",
+                true /* long_lines */));
+
   // Carriage return character.
   //
   assert (test ({{"","1"},{"a","x\ry"},{"",""},{"",""}},
@@ -241,15 +255,18 @@ main ()
   //
   assert (test ({{"","1"},{"a","abc"},{"b","bca"},{"c","cab"},{"",""},{"",""}},
                 ": 1\na: abc\nc: cab\n",
+                false /* long_lines */,
                 [] (const string& n, const string&) {return n != "b";}));
 }
 
 static string
-serialize (const pairs& m, manifest_serializer::filter_function f = {})
+serialize (const pairs& m,
+           bool long_lines = false,
+           manifest_serializer::filter_function f = {})
 {
   ostringstream os;
   os.exceptions (istream::failbit | istream::badbit);
-  manifest_serializer s (os, "", f);
+  manifest_serializer s (os, "", long_lines, f);
 
   for (const auto& p: m)
   {
@@ -263,9 +280,12 @@ serialize (const pairs& m, manifest_serializer::filter_function f = {})
 }
 
 static bool
-test (const pairs& m, const string& e, manifest_serializer::filter_function f)
+test (const pairs& m,
+      const string& e,
+      bool long_lines,
+      manifest_serializer::filter_function f)
 {
-  string r (serialize (m, f));
+  string r (serialize (m, long_lines, f));
 
   if (r != e)
   {