79 lines
1.5 KiB
C++
79 lines
1.5 KiB
C++
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// Copyright (c) 1994, 1995 James Clark
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// See the file COPYING for copying permission.
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#ifdef __GNUG__
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#pragma implementation
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#endif
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#include "splib.h"
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#include "RewindStorageObject.h"
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#include "macros.h"
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#ifdef SP_NAMESPACE
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namespace SP_NAMESPACE {
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#endif
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RewindStorageObject::RewindStorageObject(Boolean mayRewind, Boolean canSeek)
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: mayRewind_(mayRewind), canSeek_(canSeek),
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savingBytes_(mayRewind && !canSeek), readingSaved_(0)
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{
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}
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Boolean RewindStorageObject::rewind(Messenger &mgr)
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{
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ASSERT(mayRewind_);
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if (canSeek_)
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return seekToStart(mgr);
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else {
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readingSaved_ = 1;
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nBytesRead_ = 0;
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return 1;
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}
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}
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void RewindStorageObject::unread(const char *s, size_t n)
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{
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savedBytes_.append(s, n);
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if (!readingSaved_) {
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readingSaved_ = 1;
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nBytesRead_ = 0;
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}
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}
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void RewindStorageObject::willNotRewind()
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{
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mayRewind_ = 0;
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savingBytes_ = 0;
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if (!readingSaved_) {
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// Ensure that memory is released now.
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String<char> tem;
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tem.swap(savedBytes_);
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}
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}
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Boolean RewindStorageObject::readSaved(char *buf, size_t bufSize,
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size_t &nread)
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{
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if (!readingSaved_)
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return 0;
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if (nBytesRead_ >= savedBytes_.size()) {
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if (!mayRewind_) {
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// Ensure that memory is released now.
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String<char> tem;
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tem.swap(savedBytes_);
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}
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readingSaved_ = 0;
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return 0;
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}
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nread = savedBytes_.size() - nBytesRead_;
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if (nread > bufSize)
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nread = bufSize;
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memcpy(buf, savedBytes_.data() + nBytesRead_, nread);
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nBytesRead_ += nread;
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return 1;
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}
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#ifdef SP_NAMESPACE
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}
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#endif
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