Initial commit

1 files changed, 147 insertions, 0 deletions

diff --git a/sys/fmio/fmiorhdr.x b/sys/fmio/fmiorhdr.x
new file mode 100644
index 00000000..1b7f6c3c
--- /dev/null
+++ b/sys/fmio/fmiorhdr.x
@@ -0,0 +1,147 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<syserr.h>
+include	<mach.h>
+include	<knet.h>
+include	"fmio.h"
+
+# FMIO_READHEADER -- Read the header of a FMIO datafile and set up the FMIO
+# runtime descriptor.
+
+procedure fmio_readheader (fm)
+
+pointer	fm			#I FMIO descriptor
+
+pointer	sp, buf, dh, pti, pt, ft, ip, op
+int	offset, buflen, npti, p1, p2, d1, d2, b_off1, b_off2, i
+int	status, chan, nbytes, nwords, maxpages, szbpage
+errchk	syserrs, calloc, malloc, realloc
+long	clktime()
+
+begin
+	call smark (sp)
+	call salloc (dh, LEN_DHSTRUCT, TY_STRUCT)
+
+	chan = FM_CHAN(fm)
+
+	# Make a guess at the size of buffer needed to hold the header.
+	buflen = DEF_DFHDRLEN
+	call malloc (buf, buflen, TY_STRUCT)
+
+	# Read the full datafile header area into BUF.
+	repeat {
+	    # Get the raw data.
+	    nbytes = buflen * (SZ_STRUCT * SZB_CHAR)
+	    call zardbf (chan, Memi[buf], nbytes, 1)
+	    call zawtbf (chan, status)
+	    if (status == ERR)
+		call syserrs (SYS_FMRERR, FM_DFNAME(fm))
+
+	    # Extract the datafile header struct.
+	    call miiupk32 (Memi[buf], Memi[dh], LEN_DHSTRUCT, TY_STRUCT)
+	    if (DH_MAGIC(dh) != FMIO_MAGIC)
+		call syserrs (SYS_FMBADMAGIC, FM_DFNAME(fm))
+
+	    # Repeat if the full header was not read.
+	    if (DH_DATASTART(dh)-1 > nbytes) {
+		buflen = DH_DATASTART(dh)-1 / (SZ_STRUCT * SZB_CHAR)
+		call realloc (buf, buflen, TY_STRUCT)
+	    } else if (status < DH_DATASTART(dh)-1) {
+		call syserrs (SYS_FMTRUNC, FM_DFNAME(fm))
+	    } else
+		break
+	}
+
+	# Compute region of file in buffer.
+	b_off1 = 1
+	b_off2 = b_off1 + buflen * SZ_STRUCT * SZB_CHAR
+
+	# Copy general header fields.
+	FM_DFVERSION(fm)	= DH_DFVERSION(dh)
+	FM_SZBPAGE(fm)		= DH_SZBPAGE(dh)
+	FM_NLFILES(fm)		= DH_NLFILES(dh)
+	FM_DATASTART(fm)	= DH_DATASTART(dh)
+	FM_LSYNCTIME(fm)	= clktime(0)
+	FM_DHMODIFIED(fm)	= NO
+
+	# Initialize buffer sizes.
+	szbpage = FM_SZBPAGE(fm)
+	call fmio_setbuf (fm)
+	if (FM_SZBPAGE(fm) != szbpage)
+	    call syserrs (SYS_FMBLKCHSZ, FM_DFNAME(fm))
+
+	# Initialize the file table.
+	call calloc (ft, (FM_NLFILES(fm) + 1) * LEN_FTE, TY_STRUCT)
+	FM_FTOFF(fm)		= DH_FTOFF(dh)
+	FM_FTLASTNF(fm)		= DH_FTLASTNF(dh)
+	FM_FTABLE(fm)		= ft
+
+	ip = buf + FM_FTOFF(fm) - 1
+	call miiupk32 (Memi[ip], Memi[ip],
+	    (FM_NLFILES(fm) + 1) * LEN_FTEX, TY_INT)
+
+	do i = 0, FM_NLFILES(fm) {
+	    op = ft + i * LEN_FTE
+	    LF_FSIZE(op) = FT_FSIZE(ip)
+	    LF_FLAGS(op) = FT_FLAGS(ip)
+	    ip = ip + LEN_FTEX
+	}
+
+	# Read the page table index.
+	FM_PTIOFF(fm)		= DH_PTIOFF(dh)
+	FM_PTILEN(fm)		= DH_PTILEN(dh)
+	FM_PTINPTI(fm)		= DH_PTINPTI(dh)
+
+	ip = buf + FM_PTIOFF(fm) - 1
+	call malloc (pti, FM_PTILEN(fm), TY_INT)
+	call miiupk32 (Memi[ip], Memi[pti], FM_PTILEN(fm), TY_INT)
+	FM_PTINDEX(fm)		= pti
+
+	# Now read the page table itself, stored in the data pages.
+	FM_PTLEN(fm)		= DH_PTLEN(dh)
+	FM_PTNPTE(fm)		= DH_PTNPTE(dh)
+	FM_PTLUPTE(fm)		= DH_PTNPTE(dh)
+
+	call malloc (pt, FM_PTLEN(fm), TY_SHORT)
+	FM_PTABLE(fm)		= pt
+
+	maxpages = FM_MAXBUFSIZE(fm) / FM_SZBPAGE(fm)
+	if (maxpages <= 0)
+	    maxpages = DEF_BIGBUFNP
+
+	op = pt
+	npti = FM_PTINPTI(fm)
+	for (p1=1;  p1 <= npti;  p1=p2) {
+	    # Get a contiguous range of page table pages.
+	    d1 = Memi[pti+p1-1]
+	    for (p2=p1+1;  p2 <= npti;  p2=p2+1) {
+		d2 = Memi[pti+p2-1]
+		if (d2-d1 != p2-p1 || p2-p1 >= maxpages)
+		    break
+	    }
+
+	    # Read in the pages.
+	    nbytes = (p2 - p1) * FM_SZBPAGE(fm)
+	    nwords = nbytes / (SZB_CHAR * SZ_SHORT)
+	    offset = (d1-1) * FM_SZBPAGE(fm) + FM_DATASTART(fm)
+
+	    # Check to see if data is in BUF before reading datafile.
+	    if (offset >= b_off1 && (offset+nbytes) <= b_off2)
+		call bytmov (Memi[buf], offset, Mems[op], 1, nbytes)
+	    else {
+		call zardbf (chan, Mems[op], nbytes, offset)
+		call zawtbf (chan, status)
+		if (status < nbytes)
+		    call syserrs (SYS_FMTRUNC, FM_DFNAME(fm))
+	    }
+
+	    op = op + nwords
+	}
+
+	# Swap the data.
+	if (BYTE_SWAP2 == YES)
+	    call bswap2 (Mems[pt], 1, Mems[pt], 1, npti * FM_SZBPAGE(fm))
+
+	call mfree (buf, TY_STRUCT)
+	call sfree (sp)
+end