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https://github.com/Unidata/netcdf-c.git
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bf2746b8ea
re: issue https://github.com/Unidata/netcdf-c/issues/1251 Assume that you have the URL to a remote dataset which is a normal netcdf-3 or netcdf-4 file. This PR allows the netcdf-c to read that dataset's contents as a netcdf file using HTTP byte ranges if the remote server supports byte-range access. Originally, this PR was set up to access Amazon S3 objects, but it can also access other remote datasets such as those provided by a Thredds server via the HTTPServer access protocol. It may also work for other kinds of servers. Note that this is not intended as a true production capability because, as is known, this kind of access to can be quite slow. In addition, the byte-range IO drivers do not currently do any sort of optimization or caching. An additional goal here is to gain some experience with the Amazon S3 REST protocol. This architecture and its use documented in the file docs/byterange.dox. There are currently two test cases: 1. nc_test/tst_s3raw.c - this does a simple open, check format, close cycle for a remote netcdf-3 file and a remote netcdf-4 file. 2. nc_test/test_s3raw.sh - this uses ncdump to investigate some remote datasets. This PR also incorporates significantly changed model inference code (see the superceded PR https://github.com/Unidata/netcdf-c/pull/1259). 1. It centralizes the code that infers the dispatcher. 2. It adds support for byte-range URLs Other changes: 1. NC_HDF5_finalize was not being properly called by nc_finalize(). 2. Fix minor bug in ncgen3.l 3. fix memory leak in nc4info.c 4. add code to walk the .daprc triples and to replace protocol= fragment tag with a more general mode= tag. Final Note: Th inference code is still way too complicated. We need to move to the validfile() model used by netcdf Java, where each dispatcher is asked if it can process the file. This decentralizes the inference code. This will be done after all the major new dispatchers (PIO, Zarr, etc) have been implemented.
261 lines
5.0 KiB
C
261 lines
5.0 KiB
C
/* Copyright 2018, UCAR/Unidata See netcdf/COPYRIGHT file for copying
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* and redistribution conditions.*/
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/**
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* @file
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* @internal This file contains functions that return NC_EPERM, for
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* read-only dispatch layers.
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*
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* @author Ed Hartnett
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*/
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#include "ncdispatch.h"
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/**
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* @internal Not allowed for read-only access.
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*
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* @param ncid Ignored.
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* @param varid Ignored.
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* @param name Ignored.
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* @param newname Ignored.
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*
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* @return ::NC_EPERM Not allowed.
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* @author Ed Hartnett
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*/
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int
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NC_RO_rename_att(int ncid, int varid, const char *name, const char *newname)
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{
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return NC_EPERM;
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}
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/**
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* @internal Not allowed for read-only access.
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*
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* @param ncid Ignored.
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* @param varid Ignored.
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* @param name Ignored.
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*
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* @return ::NC_EPERM Not allowed.
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* @author Ed Hartnett
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*/
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int
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NC_RO_del_att(int ncid, int varid, const char *name)
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{
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return NC_EPERM;
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}
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/**
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* @internal Not allowed for read-only access.
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*
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* @param ncid Ignored.
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* @param varid Ignored.
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* @param name Ignored.
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* @param file_type Ignored.
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* @param len Ignored.
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* @param data Ignored.
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* @param memtype Ignored.
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*
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* @return ::NC_EPERM Not allowed.
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* @author Ed Hartnett
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*/
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int
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NC_RO_put_att(int ncid, int varid, const char *name, nc_type file_type,
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size_t len, const void *data, nc_type mem_type)
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{
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return NC_EPERM;
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}
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/**
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* @internal Not allowed for read-only access.
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*
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* @param ncid Ignored.
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* @param name Ignored.
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* @param len Ignored.
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* @param idp Ignored.
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*
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* @return ::NC_EPERM Not allowed.
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* @author Ed Hartnett
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*/
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int
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NC_RO_def_dim(int ncid, const char *name, size_t len, int *idp)
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{
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return NC_EPERM;
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}
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/**
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* @internal Not allowed for read-only access.
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*
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* @param ncid Ignored.
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* @param dimid Ignored.
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* @param name Ignored.
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*
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* @return ::NC_EPERM Not allowed.
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* @author Ed Hartnett
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*/
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int
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NC_RO_rename_dim(int ncid, int dimid, const char *name)
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{
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return NC_EPERM;
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}
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/**
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* @internal Not allowed for read-only access.
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*
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* @param ncid Ignored.
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* @param name Ignored.
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* @param xtype Ignored.
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* @param ndims Ignored.
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* @param dimidsp Ignored.
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* @param varidp Ignored.
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*
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* @return ::NC_EPERM Not allowed.
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* @author Ed Hartnett
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*/
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int
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NC_RO_def_var(int ncid, const char *name, nc_type xtype,
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int ndims, const int *dimidsp, int *varidp)
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{
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return NC_EPERM;
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}
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/**
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* @internal Not allowed for classic model access.
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*
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* @param ncid Ignored.
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* @param varid Ignored.
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* @param no_fill Ignored.
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* @param fill_value Ignored.
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*
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* @return ::NC_EPERM Not allowed.
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* @author Ed Hartnett
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*/
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int
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NC_RO_def_var_fill(int ncid, int varid, int no_fill, const void *fill_value)
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{
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return NC_EPERM;
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}
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/**
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* @internal Not allowed for read-only access.
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*
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* @param ncid File ID.
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* @param varid Variable ID
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* @param name New name of the variable.
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*
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* @return ::NC_EPERM Not allowed.
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* @author Ed Hartnett
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*/
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int
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NC_RO_rename_var(int ncid, int varid, const char *name)
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{
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return NC_EPERM;
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}
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/**
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* @internal Not allowed for read-only access.
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*
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* @param ncid File ID.
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* @param varid Variable ID.
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* @param startp Array of start indices.
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* @param countp Array of counts.
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* @param op pointer that gets the data.
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* @param memtype The type of these data in memory.
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*
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* @return ::NC_EPERM Not allowed.
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* @author Ed Hartnett
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*/
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int
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NC_RO_put_vara(int ncid, int varid, const size_t *startp,
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const size_t *countp, const void *op, int memtype)
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{
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return NC_EPERM;
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}
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/**
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* @internal Not allowed for read-only access.
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*
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* @param ncid File and group ID.
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* @param fillmode File mode.
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* @param old_modep Pointer that gets old mode. Ignored if NULL.
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*
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* @return ::NC_EPERM Not allowed.
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* @author Ed Hartnett
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*/
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int
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NC_RO_set_fill(int ncid, int fillmode, int *old_modep)
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{
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return NC_EPERM;
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}
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/**
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* @internal Not allowed for read-only access.
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*
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* @param ncid Ignored.
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*
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* @return ::NC_EPERM Not allowed.
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* @author Ed Hartnett
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*/
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int
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NC_RO_redef(int ncid)
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{
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return NC_EPERM;
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}
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/**
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* @internal Not allowed for read-only access.
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*
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* @param ncid Ignored.
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* @param h_minfree Ignored.
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* @param v_align Ignored.
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* @param v_minfree Ignored.
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* @param r_align Ignored.
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*
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* @return ::NC_EPERM Not allowed.
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* @author Ed Hartnett
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*/
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int
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NC_RO__enddef(int ncid, size_t h_minfree, size_t v_align,
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size_t v_minfree, size_t r_align)
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{
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return NC_NOERR;
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}
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/**
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* @internal Not allowed for read-only access.
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*
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* @param ncid Ignored.
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*
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* @return ::NC_EPERM Not allowed.
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* @author Ed Hartnett
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*/
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int
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NC_RO_sync(int ncid)
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{
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return NC_NOERR;
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}
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/**
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* @internal Not allowed for read-only access.
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*
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* @param path Ignored.
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* @param cmode Ignored.
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* @param initialsz Ignored.
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* @param basepe Ignored.
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* @param chunksizehintp Ignored.
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* @param use_parallel Ignored.
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* @param parameters Ignored.
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* @param dispatch Ignored.
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* @param nc_file Ignored.
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*
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* @return ::NC_EPERM Cannot create files.
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* @author Ed Hartnett
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*/
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int
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NC_RO_create(const char* path, int cmode, size_t initialsz, int basepe,
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size_t *chunksizehintp, void *parameters,
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NC_Dispatch *dispatch, NC *nc_file)
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{
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return NC_EPERM;
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}
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