gocept.cxoracle 0.1.1

gocept.cxoracle - 一个zc.buildout配方，可以轻松运行cx_Oracle

主要目的是设置构建cx_Oracle egg所需的环境，然后提供一个加载器，该加载器设置加载共享库所需的环境变量。

Oracle不允许自由分发所需的库。这意味着用户或开发人员必须从http://www.oracle.com/technology/software/tech/oci/instantclient/index.html下载它们

每个体系结构/操作系统需要两个存档

1. 即时客户端基本精简版

2. SDK

>>> import os.path
>>> basiclite = os.path.join(
...     os.path.dirname(__file__), 'basiclite-linux.zip')
>>> sdk = os.path.join(
...     os.path.dirname(__file__), 'sdk-linux.zip')

两个文件都必须在buildout中进行配置

>>> write("buildout.cfg", """
... [buildout]
... parts = python-oracle
... python = python-oracle
...
... [python-oracle]
... recipe = gocept.cxoracle
... instant-client = %(basiclite)s
... instant-sdk = %(sdk)s
...
... """ % {'basiclite': basiclite,
...        'sdk': sdk}
... )

>>> print system(buildout),
Installing python-oracle.

我们现在在parts中有一个oracle-home。它包含两个存档的内容 以及 一个指向libclntsh.so -> libclntsh.so.10.1的符号链接

>>> ls('parts', 'python-oracle')
-  BASIC_LITE_README
-  classes12.jar
-  genezi
-  libclntsh.so
-  libclntsh.so.10.1
-  libnnz10.so
-  libocci.so.10.1
-  libociicus.so
-  libocijdbc10.so
-  ojdbc14.jar
d  sdk

>>> import os
>>> os.path.islink(os.path.join('parts', 'python-oracle', 'libclntsh.so'))
True
>>> os.readlink(os.path.join('parts', 'python-oracle', 'libclntsh.so'))
'.../parts/python-oracle/libclntsh.so.10.1'

在bin目录中有一个包装器，该包装器设置LD_LIBRARY_PATH（或在darwin上的DYLD_LIBRARY_PATH）和ORACLE_HOME环境变量

>>> ls('bin')
-  buildout
-  python-oracle

包装器可以像任何Python解释器一样调用

>>> system(os.path.join('bin', 'python-oracle') +
...     """ -c "import os; print os.environ['ORACLE_HOME']" """)
'.../parts/python-oracle\n'

>>> script = '''\
... import os
... import sys
... if sys.platform == 'darwin':
...     varname = 'DYLD_LIBRARY_PATH'
... else:
...     varname = 'LD_LIBRARY_PATH'
... print os.environ[varname]
... '''

>>> system(os.path.join('bin', 'python-oracle') +
...     """ -c "%s" """ % script)
'.../parts/python-oracle\n'

在Mac OS X / Darwin上，库不是名为.so，而是名为.dylib。该配方正确处理了这一点

>>> basiclite = os.path.join(
...     os.path.dirname(__file__), 'basiclite-darwin.zip')
>>> sdk = os.path.join(
...     os.path.dirname(__file__), 'sdk-darwin.zip')

两个文件都必须在buildout中进行配置

>>> write("buildout.cfg", """
... [buildout]
... parts = python-oracle
... python = python-oracle
...
... [python-oracle]
... recipe = gocept.cxoracle
... instant-client = %(basiclite)s
... instant-sdk = %(sdk)s
...
... """ % {'basiclite': basiclite,
...        'sdk': sdk}
... )

>>> print system(buildout),
Uninstalling python-oracle.
Installing python-oracle.

存档像Linux一样合并，这次符号链接是libclntsh.dylib -> libclntsh.dylib.10.1

>>> ls('parts', 'python-oracle')
    -  BASIC_LITE_README
    -  classes12.jar
    -  genezi
    -  libclntsh.dylib
    -  libclntsh.dylib.10.1
    -  libnnz10.dylib
    -  libocci.dylib.10.1
    -  libociicus.dylib
    -  libocijdbc10.dylib
    -  libocijdbc10.jnilib
    -  ojdbc14.jar
    d  sdk

>>> import os
>>> os.path.islink(os.path.join('parts', 'python-oracle', 'libclntsh.dylib'))
True
>>> os.readlink(os.path.join('parts', 'python-oracle', 'libclntsh.dylib'))
'.../parts/python-oracle/libclntsh.dylib.10.1'

如果无法提取存档，我们将得到一个有用的错误

>>> write("buildout.cfg", """
... [buildout]
... parts = python-oracle
... python = python-oracle
...
... [python-oracle]
... recipe = gocept.cxoracle
... instant-client = /does/not/exist
... instant-sdk = %(sdk)s
...
... """ % {'sdk': sdk}
... )

>>> print system(buildout),
Uninstalling python-oracle.
Installing python-oracle.
While:
  Installing python-oracle.
<BLANKLINE>
An internal error occured due to a bug in either zc.buildout or in a
recipe being used:
Traceback (most recent call last):
    ...
Exception: Extraction of file '/does/not/exist' failed.

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