| 1 | /*!
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| 2 | \file tocread.c
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| 3 | \ingroup (PSIO)
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| 4 | */
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| 5 |
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| 6 | #include <unistd.h>
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| 7 | #include <stdlib.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_TOCREAD(): Read the table of contents for file number 'unit'.
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| 15 | **
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| 16 | ** \ingroup (PSIO)
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| 17 | */
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| 18 | int psio_tocread(unsigned int unit)
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| 19 | {
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| 20 | unsigned int i;
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| 21 | int errcod, stream, volume, entry_size;
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| 22 | psio_ud *this_unit;
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| 23 | psio_tocentry *last_entry, *this_entry;
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| 24 |
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| 25 | this_unit = &(psio_unit[unit]);
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| 26 | entry_size = sizeof(psio_tocentry) - 2*sizeof(psio_tocentry *);
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| 27 |
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| 28 | /* Check that this unit is actually open */
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| 29 | if(this_unit->vol[0].stream == -1) return(0);
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| 30 |
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| 31 | /* Seek vol[0] to its beginning */
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| 32 | stream = this_unit->vol[0].stream;
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| 33 | errcod = lseek(stream, 0L, SEEK_SET);
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| 34 | if(errcod == -1) psio_error(unit,PSIO_ERROR_LSEEK);
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| 35 |
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| 36 | /* Read the TOC from disk */
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| 37 | errcod = read(stream, (char *) &(this_unit->tocaddress.page),
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| 38 | sizeof(ULI));
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| 39 | if(errcod != sizeof(ULI)) return(1);
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| 40 | errcod = read(stream, (char *) &(this_unit->tocaddress.offset),
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| 41 | sizeof(ULI));
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| 42 | if(errcod != sizeof(ULI)) return(1);
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| 43 | errcod = read(stream, (char *) &(this_unit->toclen), sizeof(ULI));
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| 44 | if(errcod != sizeof(ULI)) return(1);
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| 45 |
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| 46 | /* Malloc room for the TOC */
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| 47 | this_unit->toc = (psio_tocentry *) malloc(sizeof(psio_tocentry));
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| 48 | this_entry = this_unit->toc;
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| 49 | this_entry->last = NULL;
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| 50 | for(i=1; i < this_unit->toclen; i++) {
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| 51 | last_entry = this_entry;
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| 52 | this_entry = (psio_tocentry *) malloc(sizeof(psio_tocentry));
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| 53 | last_entry->next = this_entry;
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| 54 | this_entry->last = last_entry;
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| 55 | }
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| 56 | this_entry->next = NULL;
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| 57 |
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| 58 | /* Seek the TOC volume to the correct position */
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| 59 | volume = (this_unit->tocaddress.page) % (this_unit->numvols);
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| 60 | errcod = psio_volseek(&(this_unit->vol[volume]), this_unit->tocaddress.page,
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| 61 | this_unit->tocaddress.offset, this_unit->numvols);
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| 62 | if(errcod == -1) psio_error(unit,PSIO_ERROR_LSEEK);
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| 63 |
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| 64 | /* Read the TOC entry-by-entry */
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| 65 | this_entry = this_unit->toc;
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| 66 | for(i=0; i < this_unit->toclen; i++) {
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| 67 |
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| 68 | /* This read() assumes a fixed ordering on the members of this_entry */
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| 69 | errcod = read(this_unit->vol[volume].stream, (char *) this_entry,
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| 70 | entry_size);
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| 71 | if(errcod != entry_size) psio_error(unit,PSIO_ERROR_READ);
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| 72 |
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| 73 | this_entry = this_entry->next;
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| 74 | }
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| 75 |
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| 76 | return(0);
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| 77 | }
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| 78 |
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| 79 | }
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| 80 | }
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