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Diffstat (limited to 'butl/manifest-serializer.cxx')
| -rw-r--r-- | butl/manifest-serializer.cxx | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/butl/manifest-serializer.cxx b/butl/manifest-serializer.cxx new file mode 100644 index 0000000..c45aaba --- /dev/null +++ b/butl/manifest-serializer.cxx @@ -0,0 +1,238 @@ +// file : butl/manifest-serializer.cxx -*- C++ -*- +// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd +// license : MIT; see accompanying LICENSE file + +#include <butl/manifest-serializer> + +#include <ostream> +#include <cassert> + +using namespace std; + +namespace butl +{ + using serialization = manifest_serialization; + + void manifest_serializer:: + next (const string& n, const string& v) + { + switch (s_) + { + case start: + { + if (!n.empty ()) + throw serialization (name_, "format version pair expected"); + + if (v.empty ()) + { + // End of manifests. + // + os_.flush (); + s_ = end; + break; + } + + if (v != "1") + throw serialization (name_, "unsupported format version " + v); + + os_ << ':'; + + if (v != version_) + { + os_ << ' ' << v; + version_ = v; + } + + os_ << endl; + s_ = body; + break; + } + case body: + { + if (n.empty ()) + { + if (!v.empty ()) + throw serialization (name_, "non-empty value in end pair"); + + s_ = start; + break; + } + + check_name (n); + + os_ << n << ':'; + + if (!v.empty ()) + { + os_ << ' '; + + // Use the multi-line mode in any of the following cases: + // + // - name is too long (say longer than 37 (78/2 - 2) characters; + // we cannot start on the next line since that would start the + // multi-line mode) + // - value contains newlines + // - value contains leading/trailing whitespaces + // + if (n.size () > 37 || + v.find ('\n') != string::npos || + v.front () == ' ' || v.front () == '\t' || + v.back () == ' ' || v.back () == '\t') + { + os_ << "\\" << endl; // Multi-line mode introductor. + + // Chunk the value into fragments separated by newlines. + // + for (size_t i (0), p (v.find ('\n')); ; p = v.find ('\n', i)) + { + if (p == string::npos) + { + // Last chunk. + // + write_value (0, v.c_str () + i, v.size () - i); + break; + } + + write_value (0, v.c_str () + i, p - i); + os_ << endl; + i = p + 1; + } + + os_ << endl << "\\"; // Multi-line mode terminator. + } + else + write_value (n.size () + 2, v.c_str (), v.size ()); + } + + os_ << endl; + break; + } + case end: + { + throw serialization (name_, "serialization after eos"); + } + } + } + + void manifest_serializer:: + comment (const string& t) + { + if (s_ == end) + throw serialization (name_, "serialization after eos"); + + os_ << '#'; + + if (!t.empty ()) + os_ << ' ' << t; + + os_ << endl; + } + + void manifest_serializer:: + check_name (const string& n) + { + if (n[0] == '#') + throw serialization (name_, "name starts with '#'"); + + for (char c: n) + { + switch (c) + { + case ' ': + case '\t': + case '\n': throw serialization (name_, "name contains whitespace"); + case ':': throw serialization (name_, "name contains ':'"); + default: break; + } + } + } + + void manifest_serializer:: + write_value (size_t cl, const char* s, size_t n) + { + char c ('\0'); + + // The idea is to break on the 77th character (i.e., write it + // on the next line) which means we have written 76 characters + // on this line plus 2 for '\' and '\n', which gives us 78. + // + for (const char* e (s + n); s != e; s++, cl++) + { + c = *s; + bool br (false); // Break the line. + + // If this is a whitespace, see if it's a good place to break the + // line. + // + if (c == ' ' || c == '\t') + { + // Find the next whitespace (or the end) and see if it is a better + // place. + // + for (const char* w (s + 1); ; w++) + { + if (w == e || *w == ' ' || *w == '\t') + { + // Is this whitespace past where we need to break? Also see + // below the "hard" break case for why we use 78 at the end. + // + if (cl + static_cast<size_t> (w - s) > (w != e ? 77 : 78)) + { + // Only break if this whitespace is close enough to + // the end of the line. + // + br = (cl > 57); + } + + break; + } + } + } + + // Do we have to do a "hard" break (i.e., without a whitespace)? + // If there is just one character left, then instead of writing + // '\' and then the character on the next line, we might as well + // write it on this line. + // + if (cl == (s + 1 != e ? 77 : 78)) + br = true; + + if (br) + { + os_ << '\\' << endl; + cl = 0; + } + + os_ << c; + } + + // What comes next is always a newline. I the last character that + // we have written is a backslash, escape it. + // + if (c == '\\') + os_ << '\\'; + } + + // manifest_serialization + // + + static string + format (const string& n, const string& d) + { + string r; + if (!n.empty ()) + { + r += n; + r += ": "; + } + r += "error: "; + r += d; + return r; + } + + manifest_serialization:: + manifest_serialization (const string& n, const string& d) + : runtime_error (format (n, d)), name (n), description (d) + { + } +} |