This file contains a high-level description of this package's evolution. Releases are in reverse chronological order (most recent first). Note that, as of netcdf 4.2, the `netcdf-c++` and `netcdf-fortran` libraries have been separated into their own libraries.
## 4.6.2 - TBD
## 4.6.2 - November 19, 2018
*[Enhancement] Lazy att read - only read atts when user requests one of them. See [GitHub #857](https://github.com/Unidata/netcdf-c/issues/857).
*[Enhancement] Fast global att read - when global atts are read, they are read much more quickly. See [GitHub #857](https://github.com/Unidata/netcdf-c/issues/857).
\subsection dap4_defined_params Defined Client Parameters
# Defined Client Parameters {#dap4_defined_params}
Currently, a limited set of client parameters is
recognized. Parameters not listed here are
...
...
@@ -87,12 +91,23 @@ Parameter Name Legal Values Semantics
of the complete url for every HTTP get request. If logging is
enabled, then this can be helpful in checking to see the access
behavior of the netCDF code.
\subsection dap4_debug Notes on Debugging DAP4 Access
- "translate=nc4" - This parameter causes the netCDF code to look
for specially named elements in the DMR XML in order to
achieve a better translation of the DAP4 meta-data to NetCDF enhanced
metadata.
- "opaquesize=<integer>" - This parameter causes the netCDF code to
convert DAP4 variable size OPAQUE objects to netcdf-4 fixed size
objects and forces all of them to be of the size specified.
- "fillmismatch" - Unfortunately, a number of servers sometimes
fail to make sure that the type of the "_FillValue" attribute of a variable
is the same as the type of the containing variable. Setting this tag
caused the netcdf translation to attempt to fix this mismatch. If not set,
then an error will occur.
# Notes on Debugging DAP4 Access {#dap4_debug}
The DAP4 support has a logging facility.
Note that this is currently separate from the
existing netCDF logging facility. Turning on this logging can
Turning on this logging can
sometimes give important information. Logging can be enabled by
using the client parameter "log" or "log=filename",
where the first case will send log output to standard error and the
...
...
@@ -102,4 +117,138 @@ Users should also be aware that if one is
accessing data over an NFS mount, one may see some .nfsxxxxx files;
those can be ignored.
## HTTP Configuration. {#dap4_http2_config}
Limited support for configuring the http connection is provided via
parameters in the “.daprc” configuration file (aka ".dodsrc").
The relevant .daprc file is
located by first looking in the current working directory, and if not
found, then looking in the directory specified by the “$HOME”
environment variable.
Entries in the .daprc file are of the form:
````
['['<url>']']<key>=<value>
````
That is, it consists of a key name and value pair and optionally
preceded by a url enclosed in square brackets.
For given KEY and URL strings, the value chosen is as follows:
If URL is null, then look for the .daprc entry that has no url prefix
and whose key is same as the KEY for which we are looking.
If the URL is not null, then look for all the .daprc entries that
have a url, URL1, say, and for which URL1 has the same host and port
as URL. All parts of the url's except host and port are ignored.
For example, if URL = http//x.y/a, then it will match
entries of the form
_[http//x.y/a]KEY=VALUE_ or _[http//x.y/b]KEY=VALUE_.
It will not match an entry of the form _[http//x.y:8080]KEY=VALUE
because the second has a port number (8080) different than the URL.
Finally from the set so constructed, choose the first matching entry.
Currently, the supported set of keys (with descriptions) are as
follows.
-# HTTP.VERBOSE
Type: boolean ("1"/"0")
Description: Produce verbose output, especially using SSL.
Related CURL Flags: CURLOPT_VERBOSE
-# HTTP.DEFLATE
Type: boolean ("1"/"0")
Description: Allow use of compression by the server.
Related CURL Flags: CURLOPT_ENCODING
-# HTTP.COOKIEJAR
Type: String representing file path
Description: Specify the name of file into which to store cookies. Defaults to in-memory storage.
Related CURL Flags:CURLOPT_COOKIEJAR
-# HTTP.CREDENTIALS.USER
Type: String representing user name
Description: Specify the user name for Digest and Basic authentication.
Related CURL Flags:
-# HTTP.CREDENTIALS.PASSWORD
Type: String representing password
Type: boolean ("1"/"0")
Description: Specify the password for Digest and Basic authentication.
Related CURL Flags:
-# HTTP.SSL.CERTIFICATE
Type: String representing file path
Description: Path to a file containing a PEM cerficate.
Related CURL Flags: CURLOPT_CERT
-# HTTP.SSL.KEY
Type: String representing file path
Description: Same as HTTP.SSL.CERTIFICATE, and should usually have the same value.
Related CURL Flags: CURLOPT_SSLKEY
-# HTTP.SSL.KEYPASSWORD
Type: String representing password
Description: Password for accessing the HTTP.SSL.KEY/HTTP.SSL.CERTIFICATE
Related CURL Flags: CURLOPT_KEYPASSWORD
-# HTTP.SSL.CAPATH
Type: String representing directory
Description: Path to a directory containing trusted certificates for validating server certificates.
Related CURL Flags: CURLOPT_CAPATH
-# HTTP.SSL.VALIDATE
Type: boolean ("1"/"0")
Description: Cause the client to verify the server's presented certificate.
Related CURL Flags: CURLOPT_SSL_VERIFYPEER, CURLOPT_SSL_VERIFYHOST
-# HTTP.TIMEOUT
Type: String ("dddddd")
Description: Specify the maximum time in seconds that you allow the http transfer operation to take.
Related CURL Flags: CURLOPT_TIMEOUT, CURLOPT_NOSIGNAL
-# HTTP.PROXY_SERVER
Type: String representing url to access the proxy: (e.g.http://[username:password@]host[:port])
Description: Specify the needed information for accessing a proxy.
Related CURL Flags: CURLOPT_PROXY, CURLOPT_PROXYHOST, CURLOPT_PROXYUSERPWD
-# HTTP.READ.BUFFERSIZE
Type: String ("dddddd")
Description: Specify the the internal buffer size for curl reads.
Related CURL Flags: CURLOPT_BUFFERSIZE, CURL_MAX_WRITE_SIZE (16kB),
CURL_MAX_READ_SIZE (512kB).
-# HTTP.KEEPALIVE
Type: String ("on|n/m")
Description: Specify that TCP KEEPALIVE should be enabled and that the associated idle wait time is n and that the associated repeat interval is m. If the value is of the form is the string "on", then turn on keepalive, but do not set idle or interval.
Related CURL Flags: CURLOPT_TCP_KEEPALIVE, CURLOPT_TCP_KEEPIDLE,
CURLOPT_TCP_KEEPINTVL.
The related curl flags line indicates the curl flags modified by this
key. See the libcurl documentation of the _curl_easy_setopt()_ function
for more detail (http://curl.haxx.se/libcurl/c/curl_easy_setopt.html).
For servers that require client authentication, as a rule, the following
.daprc entries should be specified.
````
HTTP.SSL.VALIDATE
HTTP.COOKIEJAR
HTTP.SSL.CERTIFICATE
HTTP.SSL.KEY
HTTP.SSL.CAPATH
````
Additionally, the _HTTP.SSL.CERTIFICATE_ and _HTTP.SSL.KEY_
entries should have same value, which is the file path for a
certificate. The HTTP.SSL.CAPATH entry should
be the path to a directory containing validation "certificates".
# Using the netCDF-C Libraries with Visual Studio {#msvc-using}
...
...
@@ -60,11 +60,11 @@ When installed, the netCDF libraries are placed in the specified locations, alon
1. When building the netCDF-C libraries with netCDF4 support, using the `Debug` libraries may cause extraneous warnings. These warnings are related to cross-dll memory management, and appear to be harmless. You can safely ignore them by using the `Release` libraries. [NCF-220]
