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Removed the UTF-32 SliceBuilder.

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This commit is contained in:
Ferdinand Majerech 2014-07-29 23:10:46 +02:00
parent 207cb249e0
commit d1aaec6a60
1 changed files with 0 additions and 247 deletions
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247
source/dyaml/reader.d
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@ -134,7 +134,6 @@ final class Reader
new ReaderException(validateResult.msg ~
validateResult.sequence.to!string));
this.sliceBuilder = SliceBuilder(this);
this.sliceBuilder8 = SliceBuilder8(this);
}
@ -301,7 +300,6 @@ final class Reader
}
/// Used to build slices of read data in Reader; to avoid allocations.
SliceBuilder sliceBuilder;
SliceBuilder8 sliceBuilder8;
/// Get a string describing current buffer position, used for error messages.
@ -627,254 +625,9 @@ private:
}
}
/// Used to build slices of already read data in Reader buffer, avoiding allocations.
///
/// Usually these slices point to unchanged Reader data, but sometimes the data is
/// changed due to how YAML interprets certain characters/strings.
///
/// See begin() documentation.
struct SliceBuilder
{
private:
// No copying by the user.
@disable this(this);
@disable void opAssign(ref SliceBuilder);
// Reader this builder works in.
Reader reader_;
// Start of the slice om reader_.buffer_ (size_t.max while no slice being build)
size_t start_ = size_t.max;
// End of the slice om reader_.buffer_ (size_t.max while no slice being build)
size_t end_ = size_t.max;
// Stack of slice ends to revert to (see Transaction)
//
// Very few levels as we don't want arbitrarily nested transactions.
size_t[4] endStack_;
// The number of elements currently in endStack_.
size_t endStackUsed_ = 0;
@safe pure nothrow const @nogc invariant()
{
if(!inProgress) { return; }
assert(end_ <= reader_.bufferOffset_, "Slice ends after buffer position");
assert(start_ <= end_, "Slice start after slice end");
}
// Is a slice currently being built?
bool inProgress() @safe pure nothrow const @nogc
{
assert(start_ == size_t.max ? end_ == size_t.max :
end_ != size_t.max, "start_/end_ are not consistent");
return start_ != size_t.max;
}
public:
/// Begin building a slice.
///
/// Only one slice can be built at any given time; before beginning a new slice,
/// finish the previous one (if any).
///
/// The slice starts at the current position in the Reader buffer. It can only be
/// extended up to the current position in the buffer; Reader methods get() and
/// forward() move the position. E.g. it is valid to extend a slice by write()-ing
/// a string just returned by get() - but not one returned by prefix() unless the
/// position has changed since the prefix() call.
void begin() @system pure nothrow @nogc
{
assert(!inProgress, "Beginning a slice while another slice is being built");
assert(endStackUsed_ == 0, "Slice stack not empty at slice begin");
start_ = reader_.bufferOffset_;
end_ = reader_.bufferOffset_;
}
/// Finish building a slice and return it.
///
/// Any Transactions on the slice must be committed or destroyed before the slice
/// is finished.
///
/// Returns a string; once a slice is finished it is definitive that its contents
/// will not be changed.
dstring finish() @system pure nothrow @nogc
{
assert(inProgress, "finish called without begin");
assert(endStackUsed_ == 0, "Finishing a slice with running transactions.");
const result = reader_.buffer_[start_ .. end_];
start_ = end_ = size_t.max;
return cast(dstring)result;
}
/// Write a string to the slice being built.
///
/// Data can only be written up to the current position in the Reader buffer.
///
/// If str is a string returned by a Reader method, and str starts right after the
/// end of the slice being built, the slice is extended (trivial operation).
///
/// See_Also: begin
void write(dchar[] str) @system pure nothrow @nogc
{
assert(inProgress, "write called without begin");
// If str starts at the end of the slice (is a string returned by a Reader
// method), just extend the slice to contain str.
if(str.ptr == reader_.buffer_.ptr + end_)
{
end_ += str.length;
}
// Even if str does not start at the end of the slice, it still may be returned
// by a Reader method and point to buffer. So we need to memmove.
else
{
core.stdc.string.memmove(reader_.buffer_.ptr + end_, cast(dchar*)str.ptr,
str.length * dchar.sizeof);
end_ += str.length;
}
}
/// Write a character to the slice being built.
///
/// Data can only be written up to the current position in the Reader buffer.
///
/// See_Also: begin
void write(dchar c) @system pure nothrow @nogc
{
assert(inProgress, "write called without begin");
reader_.buffer_[end_++] = c;
}
/// Insert a character to a specified position in the slice.
///
/// Enlarges the slice by 1 char. Note that the slice can only extend up to the
/// current position in the Reader buffer.
///
/// Params:
///
/// c = The character to insert.
/// position = Position to insert the character at in code units, not code points.
/// Must be less than slice length(); a previously returned length()
/// can be used.
void insert(const dchar c, const size_t position) @system pure nothrow @nogc
{
assert(inProgress, "insert called without begin");
assert(start_ + position <= end_, "Trying to insert after the end of the slice");
const point = start_ + position;
const movedLength = end_ - point;
if(movedLength > 0)
{
core.stdc.string.memmove(reader_.buffer_.ptr + point + 1,
reader_.buffer_.ptr + point,
movedLength * dchar.sizeof);
}
++end_;
reader_.buffer_[point] = c;
}
/// Get the current length of the slice.
size_t length() @safe pure nothrow const @nogc
{
return end_ - start_;
}
/// A slice building transaction.
///
/// Can be used to save and revert back to slice state.
struct Transaction
{
private:
// The slice builder affected by the transaction.
SliceBuilder* builder_ = null;
// Index of the return point of the transaction in StringBuilder.endStack_.
size_t stackLevel_;
// True after commit() has been called.
bool committed_;
public:
/// Begins a transaction on a SliceBuilder object.
///
/// The transaction must end $(B after) any transactions created within the
/// transaction but $(B before) the slice is finish()-ed. A transaction can be
/// ended either by commit()-ing or reverting through the destructor.
///
/// Saves the current state of a slice.
this(ref SliceBuilder builder) @system pure nothrow @nogc
{
builder_ = &builder;
stackLevel_ = builder_.endStackUsed_;
builder_.push();
}
/// Commit changes to the slice.
///
/// Ends the transaction - can only be called once, and removes the possibility
/// to revert slice state.
///
/// Does nothing for a default-initialized transaction (the transaction has not
/// been started yet).
void commit() @system pure nothrow @nogc
{
assert(!committed_, "Can't commit a transaction more than once");
if(builder_ is null) { return; }
assert(builder_.endStackUsed_ == stackLevel_ + 1,
"Parent transactions don't fully contain child transactions");
builder_.apply();
committed_ = true;
}
/// Destroy the transaction and revert it if it hasn't been committed yet.
///
/// Does nothing for a default-initialized transaction.
~this() @system pure nothrow @nogc
{
if(builder_ is null || committed_) { return; }
assert(builder_.endStackUsed_ == stackLevel_ + 1,
"Parent transactions don't fully contain child transactions");
builder_.pop();
builder_ = null;
}
}
private:
// Push the current end of the slice so we can revert to it if needed.
//
// Used by Transaction.
void push() @system pure nothrow @nogc
{
assert(inProgress, "push called without begin");
assert(endStackUsed_ < endStack_.length, "Slice stack overflow");
endStack_[endStackUsed_++] = end_;
}
// Pop the current end of endStack_ and set the end of the slice to the popped
// value, reverting changes since the old end was pushed.
//
// Used by Transaction.
void pop() @system pure nothrow @nogc
{
assert(inProgress, "pop called without begin");
assert(endStackUsed_ > 0, "Trying to pop an empty slice stack");
end_ = endStack_[--endStackUsed_];
}
// Pop the current end of endStack_, but keep the current end of the slice, applying
// changes made since pushing the old end.
//
// Used by Transaction.
void apply() @system pure nothrow @nogc
{
assert(inProgress, "apply called without begin");
assert(endStackUsed_ > 0, "Trying to apply an empty slice stack");
--endStackUsed_;
}
}
private:
// Decode an UTF-8/16/32 buffer to UTF-32 (for UTF-32 this does nothing).
//