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https://github.com/ClickHouse/ClickHouse.git
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91 lines
3.3 KiB
C++
91 lines
3.3 KiB
C++
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// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
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// Copyright (c) 2008, Google Inc.
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// All rights reserved.
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following disclaimer
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// in the documentation and/or other materials provided with the
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// distribution.
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// * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived from
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// this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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// ---
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// Author: Sanjay Ghemawat
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//
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// A printf() wrapper that writes into a fixed length buffer.
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// Useful in low-level code that does not want to use allocating
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// routines like StringPrintf().
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//
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// The implementation currently uses vsnprintf(). This seems to
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// be fine for use in many low-level contexts, but we may need to
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// rethink this decision if we hit a problem with it calling
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// down into malloc() etc.
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#ifndef BASE_RAW_PRINTER_H_
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#define BASE_RAW_PRINTER_H_
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#include <config.h>
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#include "base/basictypes.h"
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namespace base {
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class RawPrinter {
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public:
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// REQUIRES: "length > 0"
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// Will printf any data added to this into "buf[0,length-1]" and
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// will arrange to always keep buf[] null-terminated.
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RawPrinter(char* buf, int length);
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// Return the number of bytes that have been appended to the string
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// so far. Does not count any bytes that were dropped due to overflow.
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int length() const { return (ptr_ - base_); }
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// Return the number of bytes that can be added to this.
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int space_left() const { return (limit_ - ptr_); }
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// Format the supplied arguments according to the "format" string
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// and append to this. Will silently truncate the output if it does
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// not fit.
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void Printf(const char* format, ...)
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#ifdef HAVE___ATTRIBUTE__
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__attribute__ ((__format__ (__printf__, 2, 3)))
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#endif
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;
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private:
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// We can write into [ptr_ .. limit_-1].
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// *limit_ is also writable, but reserved for a terminating \0
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// in case we overflow.
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//
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// Invariants: *ptr_ == \0
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// Invariants: *limit_ == \0
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char* base_; // Initial pointer
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char* ptr_; // Where should we write next
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char* limit_; // One past last non-\0 char we can write
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DISALLOW_COPY_AND_ASSIGN(RawPrinter);
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};
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}
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#endif // BASE_RAW_PRINTER_H_
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