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Add small README on how to add additional storage backends.
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Adding additional storage backends: | ||
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- Creating a new backend: | ||
- Create a new derived class of DEVICE e.g. | ||
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class whatever_device: public DEVICE { | ||
private: | ||
POOLMEM *m_virtual_filename; | ||
boffset_t m_offset; | ||
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public: | ||
whatever_device(); | ||
~whatever_device(); | ||
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/* | ||
* Interface from DEVICE | ||
*/ | ||
int d_close(int); | ||
int d_open(const char *pathname, int flags, int mode); | ||
int d_ioctl(int fd, ioctl_req_t request, char *mt = NULL); | ||
boffset_t d_lseek(DCR *dcr, boffset_t offset, int whence); | ||
ssize_t d_read(int fd, void *buffer, size_t count); | ||
ssize_t d_write(int fd, const void *buffer, size_t count); | ||
bool d_truncate(DCR *dcr); | ||
}; | ||
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In file src/stored/backends/whatever_device.h | ||
- Create a new class implementing the pure virtual methods. | ||
In file src/stored/backends/whatever_device.c | ||
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There are plenty of examples. | ||
- Add build rules to src/stored/backends/Makefile.in | ||
- Add new backend to AVAILABLE_DEVICE_API_SRCS in src/stored/Makefile.in for non dynamic loading. | ||
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- Glue code for loading and using the new backend | ||
- Add new enum value to Device types enum in src/stored/dev.h | ||
- Add new enum value to is_file() method of DEVICE class. | ||
- Add new enum mapping to dev_types array in src/stored/stored_conf.c | ||
- For static allocation of new backend add code to m_init_dev() in src/stored/dev.c | ||
(In switch (device->dev_type) which dispatches based on device type) | ||
- Add mapping for dynamic loading of backend to src/stored/sd_backends.h |