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XRootD
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#include <XrdSsiShMat.hh>
Classes | |
struct | CRZParms |
struct | NewParms |
Public Member Functions | |
XrdSsiShMat (NewParms &parms) | |
Constructor (arguments the same as for New()) More... | |
virtual | ~XrdSsiShMat () |
Destructor. Warning, your destructor should call your own Detach()! More... | |
virtual bool | AddItem (void *newdata, void *olddata, const char *key, int hash=0, bool replace=false)=0 |
virtual bool | Attach (int tout, bool isrw=false)=0 |
virtual bool | Create (CRZParms &parms)=0 |
virtual bool | DelItem (void *data, const char *key, int hash=0)=0 |
virtual void | Detach ()=0 |
Detach the map from the shared memory. More... | |
virtual bool | Enumerate (void *&jar)=0 |
virtual bool | Enumerate (void *&jar, char *&key, void *&val)=0 |
virtual bool | Export ()=0 |
virtual bool | GetItem (void *data, const char *key, int hash=0)=0 |
virtual int | Info (const char *vname, char *buff=0, int blen=0)=0 |
virtual bool | Resize (CRZParms &parms)=0 |
virtual bool | Sync ()=0 |
virtual bool | Sync (bool dosync, bool syncdo=false)=0 |
virtual bool | Sync (int synqsz)=0 |
Static Public Member Functions | |
static XrdSsiShMat * | New (NewParms &parms) |
Protected Attributes | |
int | shmHash |
char * | shmImpl |
char * | shmPath |
char * | shmType |
int | shmTypeSz |
This class defines an abstract interface to a generic shared memory table that stores key-value pairs. Since this class a pure abstract any number of implementations may be supplied. The default one is named "XrdSsiShMam".
Definition at line 41 of file XrdSsiShMat.hh.
struct XrdSsiShMat::NewParms |
Instantiate a shared memory object.
parms | The parameters to use when creating the table. Fields are: impl Pointer to the name of the implementation that is desired. The default implementation (XrdSsiShMam) is used if nil. All processes must specify the same implementation that was used to create the table via the Create() method. If specified it must not exceed 63 characters. path Pointer to the file that is backing the table. The path is used to locate the table in memory. typeID A text name of the data type in the table. All processes must specify the same typeID that the table was created with using Create(). Specify text less than 64 characters. typesz The number of bytes occupied by the data type in the table. hashID A 4-characters text name of the hash used in the table represented as an int. All processes must specify the same hashID that the table was created with using Create(). |
Definition at line 276 of file XrdSsiShMat.hh.
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inline |
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inlinevirtual |
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pure virtual |
Add an item to the shared memory table.
newdata | Pointer to the data to be added. |
olddata | Pointer to the area where the replaced data, if any, is to be placed. |
key | The key associated with the data that is to be added. |
hash | The hash of the key that is to be used to lookup the key. If the value is zero, an internal hash is computed. |
replace | When true, if the key exists, the data associated with the key is replaced. When false, if the key exists, the addition fails with errno set to EEXIST. |
Implemented in XrdSsiShMam.
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pure virtual |
Attach this object to the shared memory associated with this object at creation time (see New() method). The attach operation waits until the shared memory file is available. At that time, the file is memory mapped.
tout | The maximum number of seconds to wait for the shared memory file to become available. If tout is zero, then the file must be immediately available. If the value is negative then the attach waits as long as needed. When tout is reached the attach fails with errno set to ETIMEDOUT. |
isrw | When true the file is mapped to writable memory and allows updates to the table. If false, the shared memory is made read/only and may be significantly faster to access. |
Implemented in XrdSsiShMam.
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pure virtual |
Implemented in XrdSsiShMam.
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pure virtual |
Delete an item from the table.
data | Pointer to the area to receive the value of the deleted key. If the pointer is nil, then the key value is not returned. |
key | Pointer to the key of length <= MaxKLen. |
hash | The hash of the key that is to be used to lookup the key. If the value is zero, an internal hash is computed. |
Implemented in XrdSsiShMam.
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pure virtual |
Detach the map from the shared memory.
Implemented in XrdSsiShMam.
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pure virtual |
Terminate an active enumeration. An active enumeration is any enumeration where the previous form of Enumerate() did not return false. Terminating an active enumeration releases all of the enumeration resources allocated.
jar | The opaque cookie initialized by a previous call to Enumerate() requesting the next key-value pair. |
Implemented in XrdSsiShMam.
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pure virtual |
Enumerate the keys and assocaited values.
jar | An opaque cookie that tracks progress. It should be initialized to zero and otherwise not touched. The same jar must be used for all successive calls. The jar is deleted when false is returned (also see the next Enumerate method). |
key | The pointer variable where the location of the key is returned upon success. |
val | The pointer variable where the location f the key values is to be returned upon success. |
Implemented in XrdSsiShMam.
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pure virtual |
Export a newly created table (i.e. see Create()).
Implemented in XrdSsiShMam.
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pure virtual |
Get an item from the table.
data | Pointer to an area to receive the value associated with key. If the pointer is nil, then the key value is not returned. |
key | Pointer to the key of length <= MaxKLen. |
hash | The hash of the key that is to be used to lookup the key. If the value is zero, an internal hash is computed. |
Implemented in XrdSsiShMam.
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pure virtual |
Return information about the table.
vname | Pointer to the variable name whose value is wanted. A particular implementation may not support all variable and may support variables not listed here. These are for the default implementation unless otherwise noted. They are: hash - name of hash being used. impl - The table implementation being used. indexsz - Number of index entries indexused - Number of index entries in use keys - Number of keys in the bale. keys/indexused is the hash table collision factor keysfree - Number of keys that can still be added maxkeylen - Longest allowed key multw - If table supports multiple writers, else 0 reuse - If table allows object reuse, else 0 type - Name of the data type in the table. typesz - The number of bytes in the table's data type |
buff | - Pointer to the buffer to receive text values. Variables that return text are: hash, impl, and type. A buffer must be supplied in any of these variables are requested. If buff is nill or too small a -1 is returned with errno set to EMSGSIZE. |
blen | The length of the buffer. |
Implemented in XrdSsiShMam.
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static |
Definition at line 39 of file XrdSsiShMat.cc.
References XrdSsiShMat::NewParms::impl.
Referenced by XrdSsi::ShMap< T >::Attach(), and XrdSsi::ShMap< T >::Create().
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pure virtual |
Resize a shared memory segment and associated file specified at object instantiation (see New() method). Resizing is implementation specific but may involve creating a new table and exporting it.
parms | Resize parameters. See the CRZParms struct for details. For resize, zero values or unspecified flags use the existing table values. |
Implemented in XrdSsiShMam.
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pure virtual |
Synchronize all modified pages to the associated backing file.
Implemented in XrdSsiShMam.
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pure virtual |
Turn memry synchronization on or off.
dosync | When true, modified table pages are written back to the backing file. The synchronous or async nature of the write is controlled by the second parameter. When false, memory-file synchronization is turned off (initial setting). |
syncdo | When true, synchronization is done in the forground. That is, a call triggering a sync will not return until complete. When false, synchronization is done in the background. |
Implemented in XrdSsiShMam.
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pure virtual |
Set the sync defer queue size.
synqsz | The maximum number of modified pages before flushing. |
Implemented in XrdSsiShMam.
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protected |
Definition at line 364 of file XrdSsiShMat.hh.
Referenced by XrdSsiShMam::Attach(), XrdSsiShMam::Create(), and XrdSsiShMam::Resize().
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protected |
Definition at line 360 of file XrdSsiShMat.hh.
Referenced by ~XrdSsiShMat(), XrdSsiShMam::Attach(), XrdSsiShMam::Create(), and XrdSsiShMam::Resize().
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protected |
Definition at line 361 of file XrdSsiShMat.hh.
Referenced by ~XrdSsiShMat(), XrdSsiShMam::Attach(), XrdSsiShMam::Create(), and XrdSsiShMam::Resize().
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protected |
Definition at line 362 of file XrdSsiShMat.hh.
Referenced by ~XrdSsiShMat(), XrdSsiShMam::Attach(), XrdSsiShMam::Create(), and XrdSsiShMam::Resize().
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protected |
Definition at line 363 of file XrdSsiShMat.hh.
Referenced by XrdSsiShMam::AddItem(), XrdSsiShMam::Attach(), XrdSsiShMam::Create(), XrdSsiShMam::DelItem(), XrdSsiShMam::GetItem(), and XrdSsiShMam::Resize().