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Commit dc3f31be authored by Michal 'vorner' Vaner's avatar Michal 'vorner' Vaner
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[2427] Separate initial token handling 

As suggested by Jinmei, extracting to separate method. Adjusting to
address changes added in between.
parent 471c6f2d
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Showing with 97 additions and 73 deletions
src/lib/dns/master_loader.cc
View file @ dc3f31be
......@@ -136,6 +136,8 @@ public:
bool loadIncremental(size_t count_limit);
MasterToken handleInitialToken();
void doOrigin(bool is_optional) {
// Parse and create the new origin. It is relative to the previous
// one.
......@@ -249,6 +251,92 @@ public:
// load?
};
// A helper method of loadIncremental, parsing the first token of a new line.
// If it looks like an RR, detect its owner name and return a string token for
// the next field of the RR.
// Otherwise, return either END_OF_LINE or END_OF_FILE token depending on
// whether the loader continues to the next line or completes the load,
// respectively. Other corner cases including $-directive handling is done
// here.
// For unexpected errors, it throws an exception, which will be handled in
// loadIncremental.
MasterToken
MasterLoader::MasterLoaderImpl::handleInitialToken() {
const MasterToken& initial_token =
lexer_.getNextToken(MasterLexer::QSTRING | MasterLexer::INITIAL_WS);
// The most likely case is INITIAL_WS, and then string/qstring. We
// handle them first.
if (initial_token.getType() == MasterToken::INITIAL_WS) {
const MasterToken& next_token = lexer_.getNextToken();
if (next_token.getType() == MasterToken::END_OF_LINE) {
return (next_token); // blank line
} else if (next_token.getType() == MasterToken::END_OF_FILE) {
lexer_.ungetToken(); // handle it in the next iteration.
eatUntilEOL(true); // effectively warn about the unexpected EOF.
return (MasterToken(MasterToken::END_OF_LINE));
}
// This means the same name as previous.
if (last_name_.get() == NULL) {
isc_throw(InternalException, "No previous name to use in "
"place of initial whitespace");
} else if (!previous_name_) {
callbacks_.warning(lexer_.getSourceName(),
lexer_.getSourceLine(),
"Ambiguous previous name previous name for "
"use in place of initial whitespace");
}
return (next_token);
} else if (initial_token.getType() == MasterToken::STRING ||
initial_token.getType() == MasterToken::QSTRING) {
// If it is name (or directive), handle it.
const MasterToken::StringRegion&
name_string(initial_token.getStringRegion());
if (name_string.len > 0 && name_string.beg[0] == '$') {
// This should have either thrown (and the error handler
// will read up until the end of line) or read until the
// end of line.
// Exclude the $ from the string on this point.
handleDirective(name_string.beg + 1, name_string.len - 1);
// So, get to the next line, there's nothing more interesting
// in this one.
return (MasterToken(MasterToken::END_OF_LINE));
}
// This should be an RR, starting with an owner name. Construct the
// name, and some string token should follow.
last_name_.reset(new Name(name_string.beg, name_string.len,
&active_origin_));
previous_name_ = true;
return (lexer_.getNextToken(MasterToken::STRING));
}
switch (initial_token.getType()) { // handle less common cases
case MasterToken::END_OF_FILE:
if (!popSource()) {
return (initial_token);
} else {
// We try to read a token from the popped source
// So retry the loop, but first, make sure the source
// is at EOL
eatUntilEOL(true);
return (MasterToken(MasterToken::END_OF_LINE));
}
case MasterToken::END_OF_LINE:
return (initial_token); // empty line
case MasterToken::ERROR:
// Error token here.
isc_throw(InternalException, initial_token.getErrorText());
default:
// Some other token (what could that be?)
isc_throw(InternalException, "Parser got confused (unexpected "
"token " << initial_token.getType() << ")");
}
}
bool
MasterLoader::MasterLoaderImpl::loadIncremental(size_t count_limit) {
if (count_limit == 0) {
......@@ -264,85 +352,21 @@ MasterLoader::MasterLoaderImpl::loadIncremental(size_t count_limit) {
size_t count = 0;
while (ok_ && count < count_limit) {
try {
MasterToken initial_token(MasterToken::NO_TOKEN_PRODUCED);
// Skip all EOLNs (empty lines) and finish on EOF
do {
initial_token = lexer_.getNextToken(MasterLexer::QSTRING |
MasterLexer::INITIAL_WS);
if (initial_token.getType() == MasterToken::INITIAL_WS) {
// The INITIAL_WS is interesting only if something is
// after it. So peek there and if there's EOLN or EOF,
// ignore it.
const MasterToken& peek_token(lexer_.getNextToken());
if (peek_token.getType() == MasterToken::END_OF_LINE ||
peek_token.getType() == MasterToken::END_OF_FILE) {
initial_token = peek_token;
} else {
// It is something interesting. Return it back and
// keep the whitespace.
lexer_.ungetToken();
}
}
if (initial_token.getType() == MasterToken::END_OF_FILE) {
if (!popSource()) {
return (true);
} else {
// We try to read a token from the popped source
// So retry the loop, but first, make sure the source
// is at EOL
eatUntilEOL(true);
continue;
}
}
} while (initial_token.getType() == MasterToken::END_OF_LINE ||
initial_token.getType() == MasterToken::END_OF_FILE);
if (initial_token.getType() == MasterToken::QSTRING ||
initial_token.getType() == MasterToken::STRING) {
// If it is name (or directive), handle it.
const MasterToken::StringRegion&
name_string(initial_token.getStringRegion());
if (name_string.len > 0 && name_string.beg[0] == '$') {
// This should have either thrown (and the error handler
// will read up until the end of line) or read until the
// end of line.
// Exclude the $ from the string on this point.
handleDirective(name_string.beg + 1, name_string.len - 1);
// So, get to the next line, there's nothing more interesting
// in this one.
continue;
}
last_name_.reset(new Name(name_string.beg, name_string.len,
&active_origin_));
previous_name_ = true;
} else if (initial_token.getType() == MasterToken::INITIAL_WS) {
// This means the same name as previous.
if (last_name_.get() == NULL) {
isc_throw(InternalException, "No previous name to use in "
"place of initial whitespace");
} else if (!previous_name_) {
callbacks_.warning(lexer_.getSourceName(),
lexer_.getSourceLine(),
"Ambiguous previous name previous name "
"for initial whitespace");
}
} else if (initial_token.getType() == MasterToken::ERROR) {
// Error token here.
isc_throw(InternalException, initial_token.getErrorText());
} else {
// Some other token (what could that be?)
isc_throw(InternalException, "Parser got confused (unexpected "
"token " << initial_token.getType() << ")");
const MasterToken next_token = handleInitialToken();
if (next_token.getType() == MasterToken::END_OF_FILE) {
return (true); // we are done
} else if (next_token.getType() == MasterToken::END_OF_LINE) {
continue; // nothing more to do in this line
}
// We are going to parse an RR, have known the owner name,
// and are now seeing the next string token in the rest of the RR.
assert(next_token.getType() == MasterToken::STRING);
// TODO: Some more flexibility. We don't allow omitting
// anything yet
// The parameters
const RRTTL ttl(getString());
const RRTTL ttl(next_token.getString());
const RRClass rrclass(getString());
const RRType rrtype(getString());
......
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