| 1 | /*!
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| 2 | \file rw.c
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| 3 | \ingroup (PSIO)
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| 4 | */
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| 5 |
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| 6 | #include <stdio.h>
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| 7 | #include <unistd.h>
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| 8 | #include <util/psi3/libpsio/psio.h>
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| 9 |
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| 10 | namespace psi3 {
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| 11 | namespace libpsio {
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| 12 |
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| 13 | /*!
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| 14 | ** PSIO_RW()
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| 15 | **
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| 16 | ** \ingroup (PSIO)
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| 17 | */
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| 18 | int psio_rw(unsigned int unit, char *buffer, psio_address address, ULI size, int wrt)
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| 19 | {
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| 20 | int errcod;
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| 21 | unsigned int i;
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| 22 | ULI errcod_uli;
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| 23 | ULI page, offset;
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| 24 | ULI buf_offset;
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| 25 | ULI this_page, this_page_max, this_page_total;
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| 26 | unsigned int first_vol, this_vol, numvols;
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| 27 | ULI bytes_left, num_full_pages;
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| 28 | psio_ud *this_unit;
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| 29 |
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| 30 | this_unit = &(psio_unit[unit]);
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| 31 | numvols = this_unit->numvols;
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| 32 | page = address.page;
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| 33 | offset = address.offset;
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| 34 |
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| 35 | /* Seek all volumes to correct starting positions */
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| 36 | first_vol = page % numvols;
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| 37 | errcod = psio_volseek(&(this_unit->vol[first_vol]), page, offset, numvols);
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| 38 | if(errcod == -1) psio_error(unit,PSIO_ERROR_LSEEK);
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| 39 | for(i=1,this_page=page+1; i < numvols; i++,this_page++) {
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| 40 | this_vol = this_page % numvols;
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| 41 | errcod = psio_volseek(&(this_unit->vol[this_vol]), this_page,
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| 42 | (ULI) 0, numvols);
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| 43 | if(errcod == -1) psio_error(unit,PSIO_ERROR_LSEEK);
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| 44 | }
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| 45 |
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| 46 | /* Number of bytes left on the first page */
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| 47 | this_page_max = PSIO_PAGELEN - offset;
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| 48 |
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| 49 | /* If we have enough room on this page, use it */
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| 50 | if(size <= this_page_max) this_page_total = size;
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| 51 | else this_page_total = this_page_max;
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| 52 |
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| 53 | buf_offset = 0;
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| 54 | if(wrt) {
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| 55 | errcod_uli = write(this_unit->vol[first_vol].stream, &(buffer[buf_offset]),
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| 56 | this_page_total);
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| 57 | if(errcod_uli != this_page_total) psio_error(unit,PSIO_ERROR_WRITE);
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| 58 | }
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| 59 | else {
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| 60 | errcod_uli = read(this_unit->vol[first_vol].stream, &(buffer[buf_offset]),
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| 61 | this_page_total);
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| 62 | if(errcod_uli != this_page_total) psio_error(unit,PSIO_ERROR_READ);
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| 63 | }
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| 64 |
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| 65 | /* Total number of bytes remaining to be read/written */
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| 66 | bytes_left = size - this_page_total;
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| 67 |
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| 68 | /* Read/Write all the full pages */
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| 69 | num_full_pages = bytes_left/PSIO_PAGELEN;
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| 70 | buf_offset += this_page_total;
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| 71 | for(i=0,this_page=page+1; i < num_full_pages; i++,this_page++) {
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| 72 | this_vol = this_page % numvols;
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| 73 | this_page_total = PSIO_PAGELEN;
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| 74 | if(wrt) {
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| 75 | errcod_uli = write(this_unit->vol[this_vol].stream, &(buffer[buf_offset]),
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| 76 | this_page_total);
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| 77 | if(errcod_uli != this_page_total) psio_error(unit,PSIO_ERROR_WRITE);
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| 78 | }
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| 79 | else {
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| 80 | errcod_uli = read(this_unit->vol[this_vol].stream, &(buffer[buf_offset]),
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| 81 | this_page_total);
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| 82 | if(errcod_uli != this_page_total) psio_error(unit,PSIO_ERROR_READ);
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| 83 | }
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| 84 | buf_offset += this_page_total;
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| 85 | }
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| 86 |
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| 87 | /* Read/Write the final partial page */
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| 88 | bytes_left -= num_full_pages * PSIO_PAGELEN;
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| 89 | this_vol = this_page % numvols;
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| 90 | if(bytes_left) {
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| 91 | if(wrt) {
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| 92 | errcod_uli = write(this_unit->vol[this_vol].stream, &(buffer[buf_offset]),
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| 93 | bytes_left);
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| 94 | if(errcod_uli != bytes_left) psio_error(unit,PSIO_ERROR_WRITE);
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| 95 | }
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| 96 | else {
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| 97 | errcod_uli = read(this_unit->vol[this_vol].stream, &(buffer[buf_offset]),
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| 98 | bytes_left);
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| 99 | if(errcod_uli != bytes_left) psio_error(unit,PSIO_ERROR_READ);
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| 100 | }
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| 101 | }
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| 102 |
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| 103 | return(0);
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| 104 | }
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| 105 |
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| 106 | }
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| 107 | }
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