1 | /* |
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2 | * Copyright (C) 1996-2015 The Squid Software Foundation and contributors |
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3 | * |
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4 | * Squid software is distributed under GPLv2+ license and includes |
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5 | * contributions from numerous individuals and organizations. |
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6 | * Please see the COPYING and CONTRIBUTORS files for details. |
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7 | */ |
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8 | |
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9 | #ifndef SQUID_DISKFILE_H |
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10 | #define SQUID_DISKFILE_H |
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11 | |
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12 | #include "base/RefCount.h" |
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13 | #include "typedefs.h" |
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14 | |
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15 | class IORequestor; |
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16 | |
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17 | class ReadRequest; |
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18 | |
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19 | class WriteRequest; |
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20 | |
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21 | class DiskFile : public RefCountable |
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22 | { |
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23 | |
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24 | public: |
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25 | |
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26 | /// generally useful configuration options supported by some children |
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27 | class Config |
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28 | { |
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29 | public: |
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30 | Config(): ioTimeout(0), ioRate(-1) {} |
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31 | |
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32 | /// canRead/Write should return false if expected I/O delay exceeds it |
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33 | time_msec_t ioTimeout; // not enforced if zero, which is the default |
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34 | |
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35 | /// shape I/O request stream to approach that many per second |
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36 | int ioRate; // not enforced if negative, which is the default |
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37 | }; |
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38 | |
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39 | typedef RefCount<DiskFile> Pointer; |
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40 | |
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41 | /// notes supported configuration options; kids must call this first |
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42 | virtual void configure(const Config &cfg) {} |
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43 | |
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44 | virtual void open(int flags, mode_t mode, RefCount<IORequestor> callback) = 0; |
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45 | virtual void create(int flags, mode_t mode, RefCount<IORequestor> callback) = 0; |
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46 | virtual void read(ReadRequest *) = 0; |
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47 | virtual void write(WriteRequest *) = 0; |
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48 | virtual void close() = 0; |
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49 | virtual bool canRead() const = 0; |
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50 | virtual bool canWrite() const {return true;} |
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51 | |
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52 | /** During migration only */ |
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53 | virtual int getFD() const {return -1;} |
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54 | |
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55 | virtual bool error() const = 0; |
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56 | |
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57 | /** Inform callers if there is IO in progress */ |
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58 | virtual bool ioInProgress() const = 0; |
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59 | }; |
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60 | |
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61 | #endif /* SQUID_DISKFILE_H */ |
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62 | |
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