On Fri, Aug 9, 2019 at 6:36 PM Robert Haas <robertmh...@gmail.com> wrote:
> On Wed, Aug 7, 2019 at 5:46 AM Jeevan Chalke > <jeevan.cha...@enterprisedb.com> wrote: > > So, do you mean we should just do fread() and fwrite() for the whole > file? > > > > I thought it is better if it was done by the OS itself instead of > reading 1GB > > into the memory and writing the same to the file. > > Well, 'cp' is just a C program. If they can write code to copy a > file, so can we, and then we're not dependent on 'cp' being installed, > working properly, being in the user's path or at the hard-coded > pathname we expect, etc. There's an existing copy_file() function in > src/backed/storage/file/copydir.c which I'd probably look into > adapting for frontend use. I'm not sure whether it would be important > to adapt the data-flushing code that's present in that routine or > whether we could get by with just the loop to read() and write() data. > Agree that we can certainly use open(), read(), write(), and close() here, but given that pg_basebackup.c and basbackup.c are using file operations, I think using fopen(), fread(), fwrite(), and fclose() will be better here, at-least for consistetncy. Let me know if we still want to go with native OS calls. > > -- > Robert Haas > EnterpriseDB: http://www.enterprisedb.com > The Enterprise PostgreSQL Company > -- Jeevan Chalke Technical Architect, Product Development EnterpriseDB Corporation The Enterprise PostgreSQL Company
