#include <ISmbios.h>
Inheritance diagram for ISmbiosItem:
Public Types | |
enum | { FIELD_LEN_BYTE = 1, FIELD_LEN_WORD = 2, FIELD_LEN_DWORD = 4, FIELD_LEN_QWORD = 8 } |
Public Member Functions | |
virtual | ~ISmbiosItem () |
ISmbiosItem () | |
virtual std::auto_ptr< const ISmbiosItem > | clone () const=0 |
virtual std::auto_ptr< ISmbiosItem > | clone ()=0 |
virtual std::ostream & | streamify (std::ostream &cout) const=0 |
virtual u8 | getType () const=0 |
virtual u8 | getLength () const=0 |
virtual u16 | getHandle () const=0 |
virtual void | getData (unsigned int offset, void *out, size_t size) const =0 |
virtual const u8 * | getBufferCopy (size_t &length) const=0 |
virtual const size_t | getBufferSize () const=0 |
Returns the buffer size of the item. | |
virtual const char * | getStringByStringNumber (u8) const=0 |
Theory of Operation
The ISmbiosItem class models access to individual items in the SMBIOS table. It does this by providing a set of accessor functions that allow structured data to be pulled out of the item.
There are two modes of operation, depending on how the ISmbiosTable is set up. First, normal mode allows clients to access any information in the Item by offset and length. This access mode imposes no checks or typing requirements on the data being accessed aside from bounds checking that no buffer overruns occur. The drawback of this mode is that the client code must always know the exact data length and offset of any data that they want to extract.
The next mode of operation is XML enhanced operation. In this mode, the client can pass in strings representing what data is requested. The item will use an XML file to look up the exact offset of this data using the string passed as a referenced. Then the item returns the data to the client. The advantage of this access mode is that data is strongly typed, and the client is prevented from invalid access modes. For example, they may not access half of a u16 data item using the getU8() function call.
Class Hierarchy
The class heirarchy for ISmbiosItem is simple. The abstract interface class is ISmbiosItem. The full implementation of normal-mode access is in SmbiosItem, and the XML enhanced mode access is implemented in SmbiosItemXml (formerly SmbiosItemAccess).
Implementation
The SmbiosItem is implemented with its own data buffer for item data. This is reasonable as the max size for any single item is 256 bytes of data. Upon construction, the Item copies the relevant item data out of the containing table and from then maintains its own memory buffer.
Lifetime and Ownership
The SmbiosItem is destroyed when the containing table is destroyed. There is no method to allow the table to release an item. The copy constructor is purposefully made 'private' to the Item to disallow third parties from taking bad references to individual items.
Definition at line 275 of file ISmbios.h.
anonymous enum |
~ISmbiosItem | ( | ) | [virtual] |
Destructor
Definition at line 34 of file SmbiosItem.cpp.
ISmbiosItem | ( | ) |
Definition at line 37 of file SmbiosItem.cpp.
virtual std::auto_ptr<const ISmbiosItem> clone | ( | ) | const [pure virtual] |
Implemented in SmbiosItem.
virtual std::auto_ptr<ISmbiosItem> clone | ( | ) | [pure virtual] |
Implemented in SmbiosItem.
virtual std::ostream& streamify | ( | std::ostream & | cout | ) | const [pure virtual] |
Used by 'stdostream &smbios::operator <<( std::ostream &, ISmbiosItem&)' to print out the item info.
Not particularly useful for clients. Use operator<< instead.
Implemented in SmbiosItem.
Referenced by smbios::operator<<().
virtual u8 getType | ( | ) | const [pure virtual] |
Returns the Type field of the SMBIOS Item. This field is standard for all SMBIOS tables and is defined in the SMBIOS standard.
Implemented in SmbiosItem.
Referenced by SmbiosWorkaroundTable::fixupItem(), smbios::getBits_FromItem(), smbios::getData_UsingXml(), smbios::getString_FromItem(), and testStandalone::testItemIdentity().
virtual u8 getLength | ( | ) | const [pure virtual] |
Returns the Length field of the SMBIOS Item. This field is standard for all SMBIOS tables and is defined in the SMBIOS standard.
Implemented in SmbiosItem.
virtual u16 getHandle | ( | ) | const [pure virtual] |
Returns the Handle field of the SMBIOS Item. This field is standard for all SMBIOS tables and is defined in the SMBIOS standard.
Implemented in SmbiosItem.
virtual void getData | ( | unsigned int | offset, | |
void * | out, | |||
size_t | size | |||
) | const [pure virtual] |
Set of accessor functions: getU8(), getU16(), getU32(), and getU64() Returns a (byte|word|dword|qword) field from the Item.
The offset specified is an int representing the a valid offset within the table. Method will return a u8/u16/u32/u64 (depending on function called).
These methods all check the offset parameter for out of bounds conditions. They will throw exceptions on attempts to access data outside the length of the present item.
offset | The offset to the field within the Item. | |
out | void pointer to where to store output data | |
size | size of data to return |
Implemented in SmbiosItem.
Referenced by smbios::compare(), smbios::getBits_FromItem(), smbios::getData(), smbios::getData_UsingXml(), smbios::getU16_FromItem(), smbios::getU32_FromItem(), smbios::getU64_FromItem(), and smbios::getU8_FromItem().
virtual const u8* getBufferCopy | ( | size_t & | length | ) | const [pure virtual] |
Implemented in SmbiosItem.
virtual const size_t getBufferSize | ( | ) | const [pure virtual] |
virtual const char* getStringByStringNumber | ( | u8 | ) | const [pure virtual] |
Not likely to be useful to regular client code. It is public mainly to help in writing Unit Tests. Clients should normally use getString().
Implemented in SmbiosItem.
Referenced by smbios::getString_FromItem().