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improving documentation
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@edwardhartnett
edwardhartnett committed May 10, 2024
1 parent 753d207 commit 04fad7e
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Showing 2 changed files with 105 additions and 36 deletions.
41 changes: 28 additions & 13 deletions src/g2index.F90
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Original file line number Diff line number Diff line change
Expand Up @@ -1190,7 +1190,9 @@ end subroutine ixgb2
!> @param lskip8 Number of bytes to skip before GRIB message.
!> @param idxver Index version, use 1 for legacy, 2 for GRIB2 files > 2 GB.
!> @param lgrib8 Number of bytes in GRIB message. When subroutine is
!> called, this must be set to the size of the cbuf buffer.
!> called, if this is < 5000, it will be used as the number of bytes
!> initially read from the file. So for GRIB2 messages of < 5000 in
!> size, this should be set to the size of the GRIB2 message.
!> @param cbuf Pointer to a buffer that will get the index
!> records. If any memory is associated with cbuf when this subroutine
!> is called, cbuf will be nullified in the subroutine. Initially cbuf
Expand Down Expand Up @@ -1226,20 +1228,20 @@ subroutine ix2gb2(lugb, lskip8, idxver, lgrib8, cbuf, numfld, mlen, iret)
integer :: indbmp, numsec, next, newsize, g2_mova2i, mbuf, lindex
integer :: linmax, ixskp
integer :: mxspd, mxskp, mxsgd, mxsdr, mxsbm, mxlus
integer :: mxlen, mxds, mxfld, mxbms
integer :: mxlen, mxds, mxfld, MXBMS
integer :: init, ixlus, lskip
integer :: ixsgd, ilndrs, ilnpds, istat, ixds
integer (kind = 8) :: ibread8, lbread8, ibskip8, lengds8
integer (kind = 8) :: ilnpds8, ilndrs8
integer :: ixspd, ixfld, ixids, ixlen, ixsbm, ixsdr
integer :: lensec, lensec1
parameter(linmax = 5000, init = 50000, next = 10000)
parameter(LINMAX = 5000, INIT = 50000, next = 10000)
parameter(ixskp = 4, ixlus = 8, ixsgd = 12, ixspd = 16, ixsdr = 20, ixsbm = 24, &
ixds = 28, ixlen = 36, ixfld = 42, ixids = 44)
parameter(mxskp = 4, mxlus = 4, mxsgd = 4, mxspd = 4, mxsdr = 4, mxsbm = 4, &
mxds = 4, mxlen = 4, mxfld = 2, mxbms = 6)
character cbread(linmax), cindex(linmax)
character cids(linmax), cgds(linmax)
mxds = 4, mxlen = 4, mxfld = 2, MXBMS = 6)
character cbread(LINMAX), cindex(LINMAX)
character cids(LINMAX), cgds(LINMAX)
integer :: INT1_BITS, INT2_BITS, INT4_BITS, INT8_BITS
parameter(INT1_BITS = 8, INT2_BITS = 16, INT4_BITS = 32, INT8_BITS = 64)
integer :: mypos, inc
Expand All @@ -1252,39 +1254,52 @@ subroutine ix2gb2(lugb, lskip8, idxver, lgrib8, cbuf, numfld, mlen, iret)
inc = 12
endif

! Initialize values and allocate buffer to read data into.
loclus = 0
loclus8 = 0
iret = 0
mlen = 0
numfld = 0
nullify(cbuf)
mbuf = init
mbuf = INIT
allocate(cbuf(mbuf), stat = istat) ! allocate initial space for cbuf
if (istat .ne. 0) then
iret = 1
return
endif

! Read sections 0 and 1 for GRIB version number and discipline.
ibread8 = min(lgrib8, linmax)
! Read up to 5000 bytes from the file into buffer cbread. lskip8
! must be set to the beginning of a GRIB2 message in the file.
ibread8 = min(lgrib8, LINMAX)
call bareadl(lugb, lskip8, ibread8, lbread8, cbread)
if (lbread8 .ne. ibread8) then
iret = 2
return
endif

! Check GRIB version from section 0, must be 2.
if(cbread(8) .ne. char(2)) then ! not grib edition 2
iret = 3
return
endif

! Remember the GRIB version and discipline.
cver = cbread(8)
cdisc = cbread(7)

! Read the length of section 1 from the buffer.
call g2_gbytec(cbread, lensec1, 16 * 8, INT4_BITS)
lensec1 = min(lensec1, int(ibread8, kind(lensec1)))

! Copy section 1 values into cids array.
cids(1:lensec1) = cbread(17:16 + lensec1)

! Skip past section 1 in the data buffer.
ibskip8 = lskip8 + 16_8 + int(lensec1, kind(8))

! Loop through remaining sections creating an index for each field.
ibread8 = max(5, mxbms)
! Loop through remaining sections creating an index for each
! field. This overwrites the cbread data buffer.
ibread8 = max(5, MXBMS)
do
call bareadl(lugb, ibskip8, ibread8, lbread8, cbread)
ctemp = cbread(1)//cbread(2)//cbread(3)//cbread(4)
Expand Down Expand Up @@ -1372,8 +1387,8 @@ subroutine ix2gb2(lugb, lskip8, idxver, lgrib8, cbuf, numfld, mlen, iret)
elseif (indbmp.eq.255) then
call g2_sbytec(cindex, int(ibskip8 - lskip8, kind(4)), mypos, INT4_BITS) ! loc. of bms
endif
cindex(lindex + 1:lindex + mxbms) = cbread(1:mxbms)
lindex = lindex + mxbms
cindex(lindex + 1:lindex + MXBMS) = cbread(1:MXBMS)
lindex = lindex + MXBMS
call g2_sbytec(cindex, lindex, 0, INT4_BITS) ! num bytes in index record
elseif (numsec .eq. 7) then ! found data section
mypos = (ixds + inc) * INT1_BITS
Expand Down
100 changes: 77 additions & 23 deletions tests/test_ix2gb2.F90
View file
Original file line number Diff line number Diff line change
Expand Up @@ -8,17 +8,25 @@ program test_ix2gb2
implicit none

character(*) :: TEST_FILE_WW3_WEST
parameter (TEST_FILE_WW3_WEST = 'data/WW3_Regional_US_West_Coast_20220718_0000.grib2')
parameter (TEST_FILE_WW3_WEST = 'gdaswave.t00z.wcoast.0p16.f000.grib2')
integer :: lugi = 3
character(len=1), pointer, dimension(:) :: cbuf(:)
character :: expected_cbuf(200)
integer :: lskip, lgrib, numfld, mlen, iret, i
integer :: numfld, mlen, iret, i
integer (kind = 8) :: lskip8, lgrib8
integer :: idxver = 1

! integer :: index_rec_len, b2s_message, b2s_lus, b2s_gds, b2s_pds, b2s_drs, b2s_bms, b2s_data
! integer :: total_bytes, grib_version, discipline, field_number, inc

interface
subroutine ixgb2(lugb, lskip, lgrib, cbuf, numfld, mlen, iret)
integer lugb, lskip, lgrib, numfld, mlen, iret
character(len = 1),pointer,dimension(:) :: cbuf
end subroutine ixgb2
subroutine ix2gb2(lugb, lskip8, idxver, lgrib8, cbuf, numfld, mlen, iret)
integer :: lugb
integer (kind = 8) :: lskip8
integer :: idxver
integer (kind = 8) :: lgrib8
character(len = 1), pointer, dimension(:) :: cbuf
integer :: numfld, mlen, iret
end subroutine ix2gb2
end interface

call baopenr(lugi, TEST_FILE_WW3_WEST, iret)
Expand All @@ -29,24 +37,70 @@ end subroutine ixgb2

! This will return an error because lskip does not point to a valid
! GRIB message.
lskip = 0
lgrib = 11183
call ixgb2(lugi, lskip, lgrib, cbuf, numfld, mlen, iret)
if (iret .ne. 3) stop 11
! lskip8 = 0
! lgrib8 = 5000
! call ix2gb2(lugi, lskip8, idxver, lgrib8, cbuf, numfld, mlen, iret)
! if (iret .ne. 3) stop 11

! ! Free allocated memory
! deallocate(cbuf)

! ! These numbers come from test_skgb.F90, which finds the
! ! offsets/lengths of all GRIB messages in this test file.
! lskip = 202
! lgrib = 11183
! call ixgb2(lugi, lskip, lgrib, cbuf, numfld, mlen, iret)
! if (numfld .ne. 1 .or. mlen .ne. 200 .or. iret .ne. 0) stop 20
! !print *,cbuf(1:mlen)

! ! Break out the index record into component values.
! if (idxver .eq. 1) then
! inc = 0
! call g2_gbytec(cbuf, index_rec_len, 0, 8 * 4)
! if (index_rec_len .ne. 200) stop 105
! print *, 'index_rec_len', index_rec_len
! call g2_gbytec(cbuf, b2s_message, 8 * 4, 8 * 4)
! if (b2s_message .ne. 202) stop 106
! call g2_gbytec(cbuf, b2s_lus, 8 * 8, 8 * 4)
! if (b2s_lus .ne. 0) stop 107
! call g2_gbytec(cbuf, b2s_gds, 8 * 12, 8 * 4)
! if (b2s_gds .ne. 37) stop 108
! else
! inc = 16
! call g2_gbytec(cbuf, index_rec_len, 0, 8 * 8)
! if (index_rec_len .ne. 200) stop 105
! print *, 'index_rec_len', index_rec_len
! call g2_gbytec(cbuf, b2s_message, 8 * 8, 8 * 8)
! if (b2s_message .ne. 202) stop 106
! call g2_gbytec(cbuf, b2s_lus, 8 * 8, 8 * 8)
! if (b2s_lus .ne. 0) stop 107
! call g2_gbytec(cbuf, b2s_gds, 8 * 12, 8 * 8)
! if (b2s_gds .ne. 37) stop 108
! ! call g2_gbytec(cbuf, b2s_pds, 8 * 16, 8 * 8)
! ! if (b2s_pds .ne. 109) stop 109
! endif
! call g2_gbytec(cbuf, b2s_pds, 8 * 16, 8 * 4)
! if (b2s_pds .ne. 109) stop 109
! call g2_gbytec(cbuf, b2s_drs, inc + 8 * 20, 8 * 4)
! if (b2s_drs .ne. 143) stop 110
! call g2_gbytec(cbuf, b2s_bms, inc + 8 * 24, 8 * 4)
! if (b2s_bms .ne. 166) stop 111
! call g2_gbytec(cbuf, b2s_data, inc + 8 * 28, 8 * 4)
! if (b2s_data .ne. 4721) stop 112
! call g2_gbytec(cbuf, total_bytes, inc + 8 * 32, 8 * 8)
! if (total_bytes .ne. 11183) stop 113
! call g2_gbytec(cbuf, grib_version, inc + 8 * 40, 8 * 1)
! if (grib_version .ne. 2) stop 113
! call g2_gbytec(cbuf, discipline, inc + 8 * 41, 8 * 1)
! if (discipline .ne. 10) stop 113
! call g2_gbytec(cbuf, field_number, inc + 8 * 42, 8 * 2)
! if (field_number .ne. 1) stop 113
! print *, 'index_rec_len = ', index_rec_len, ' b2s_message = ', b2s_message
! print *, 'b2s_lus, b2s_gds, b2s_pds, b2s_drs, b2s_bms, b2s_data: ', b2s_lus, b2s_gds, b2s_pds, b2s_drs, b2s_bms, b2s_data
! print *, 'total_bytes, grib_version, discipline, field_number: ', total_bytes, grib_version, discipline, field_number

! Free allocated memory
deallocate(cbuf)

! These numbers come from test_skgb.F90, which finds the
! offsets/lengths of all GRIB messages in this test file.
lskip = 202
lgrib = 11183
call ixgb2(lugi, lskip, lgrib, cbuf, numfld, mlen, iret)
if (numfld .ne. 1 .or. mlen .ne. 200 .or. iret .ne. 0) stop 20
!print *,cbuf(1:mlen)

! Free allocated memory
deallocate(cbuf)
!deallocate(cbuf)

call baclose(lugi, iret)
if (iret .ne. 0) then
Expand Down

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