Add ExternalData module

Take files we previously distributed in ITK 4.3.1:

  CMake/ExternalData.cmake
  CMake/ExternalData_config.cmake.in

and add them for distribution in upstream CMake.  Update the copyright
notice block format to follow CMake conventions.
This commit is contained in:
Brad King 2013-01-24 13:29:48 -05:00
parent 21fc6c46df
commit ab26249db1
2 changed files with 714 additions and 0 deletions

710
Modules/ExternalData.cmake Normal file
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# - Manage data files stored outside source tree
# Use this module to unambiguously reference data files stored outside the
# source tree and fetch them at build time from arbitrary local and remote
# content-addressed locations. Functions provided by this module recognize
# arguments with the syntax "DATA{<name>}" as references to external data,
# replace them with full paths to local copies of those data, and create build
# rules to fetch and update the local copies.
#
# The DATA{} syntax is literal and the <name> is a full or relative path
# within the source tree. The source tree must contain either a real data
# file at <name> or a "content link" at <name><ext> containing a hash of the
# real file using a hash algorithm corresponding to <ext>. For example, the
# argument "DATA{img.png}" may be satisfied by either a real "img.png" file in
# the current source directory or a "img.png.md5" file containing its MD5 sum.
#
# The 'ExternalData_Expand_Arguments' function evaluates DATA{} references
# in its arguments and constructs a new list of arguments:
# ExternalData_Expand_Arguments(
# <target> # Name of data management target
# <outVar> # Output variable
# [args...] # Input arguments, DATA{} allowed
# )
# It replaces each DATA{} reference in an argument with the full path of a
# real data file on disk that will exist after the <target> builds.
#
# The 'ExternalData_Add_Test' function wraps around the CMake add_test()
# command but supports DATA{} references in its arguments:
# ExternalData_Add_Test(
# <target> # Name of data management target
# ... # Arguments of add_test(), DATA{} allowed
# )
# It passes its arguments through ExternalData_Expand_Arguments and then
# invokes add_test() using the results.
#
# The 'ExternalData_Add_Target' function creates a custom target to manage
# local instances of data files stored externally:
# ExternalData_Add_Target(
# <target> # Name of data management target
# )
# It creates custom commands in the target as necessary to make data files
# available for each DATA{} reference previously evaluated by other functions
# provided by this module. A list of URL templates must be provided in the
# variable ExternalData_URL_TEMPLATES using the placeholders "%(algo)" and
# "%(hash)" in each template. Data fetch rules try each URL template in order
# by substituting the hash algorithm name for "%(algo)" and the hash value for
# "%(hash)".
#
# The following hash algorithms are supported:
# %(algo) <ext> Description
# ------- ----- -----------
# MD5 .md5 Message-Digest Algorithm 5, RFC 1321
# Note that the hashes are used only for unique data identification and
# download verification. This is not security software.
#
# Example usage:
# include(ExternalData)
# set(ExternalData_URL_TEMPLATES "file:///local/%(algo)/%(hash)"
# "http://data.org/%(algo)/%(hash)")
# ExternalData_Add_Test(MyData
# NAME MyTest
# COMMAND MyExe DATA{MyInput.png}
# )
# ExternalData_Add_Target(MyData)
# When test "MyTest" runs the "DATA{MyInput.png}" argument will be replaced by
# the full path to a real instance of the data file "MyInput.png" on disk. If
# the source tree contains a content link such as "MyInput.png.md5" then the
# "MyData" target creates a real "MyInput.png" in the build tree.
#
# The DATA{} syntax can automatically recognize and fetch a file series. If
# the source tree contains a group of files or content links named like a
# series then a DATA{} reference to one member adds rules to fetch all of
# them. Although all members of a series are fetched, only the file
# originally named by the DATA{} argument is substituted for it. Two
# variables configure recognition of a series from DATA{<name>}. First,
# ExternalData_SERIES_PARSE is a regex of the form "^(...)(...)(...)$" to
# parse <prefix>, <number>, and <suffix> parts from <name>. Second,
# ExternalData_SERIES_MATCH is a regex matching the <number> part of series
# members named <prefix><number><suffix>. Note that the <suffix> of a series
# does not include a hash-algorithm extension. Both series configuration
# variables have default values that work well for common cases.
#
# The DATA{} syntax can alternatively match files associated with the named
# file and contained in the same directory. Associated files may be specified
# by options using the syntax DATA{<name>,<opt1>,<opt2>,...}. Each option may
# specify one file by name or specify a regular expression to match file names
# using the syntax REGEX:<regex>. For example, the arguments
# DATA{MyData/MyInput.mhd,MyInput.img} # File pair
# DATA{MyData/MyFrames00.png,REGEX:MyFrames[0-9]+\\.png} # Series
# will pass MyInput.mha and MyFrames00.png on the command line but ensure
# that the associated files are present next to them.
#
# The variable ExternalData_LINK_CONTENT may be set to the name of a supported
# hash algorithm to enable automatic conversion of real data files referenced
# by the DATA{} syntax into content links. For each such <file> a content
# link named "<file><ext>" is created. The original file is renamed to the
# form ".ExternalData_<algo>_<hash>" to stage it for future transmission to
# one of the locations in the list of URL templates (by means outside the
# scope of this module). The data fetch rule created for the content link
# will use the staged object if it cannot be found using any URL template.
#
# The variable ExternalData_OBJECT_STORES may be set to a list of local
# directories that store objects using the layout <dir>/%(algo)/%(hash).
# These directories will be searched first for a needed object. If the object
# is not available in any store then it will be fetched remotely using the URL
# templates and added to the first local store listed. If no stores are
# specified the default is a location inside the build tree.
#
# The variable ExternalData_SOURCE_ROOT may be set to the highest source
# directory containing any path named by a DATA{} reference. The default is
# CMAKE_SOURCE_DIR. ExternalData_SOURCE_ROOT and CMAKE_SOURCE_DIR must refer
# to directories within a single source distribution (e.g. they come together
# in one tarball).
#
# The variable ExternalData_BINARY_ROOT may be set to the directory to hold
# the real data files named by expanded DATA{} references. The default is
# CMAKE_BINARY_DIR. The directory layout will mirror that of content links
# under ExternalData_SOURCE_ROOT.
#
# Variables ExternalData_TIMEOUT_INACTIVITY and ExternalData_TIMEOUT_ABSOLUTE
# set the download inactivity and absolute timeouts, in seconds. The defaults
# are 60 seconds and 300 seconds, respectively. Set either timeout to 0
# seconds to disable enforcement. The inactivity timeout is enforced only
# with CMake >= 2.8.5.
#=============================================================================
# Copyright 2010-2013 Kitware, Inc.
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)
function(ExternalData_add_test target)
ExternalData_expand_arguments("${target}" testArgs ${ARGN})
add_test(${testArgs})
endfunction()
function(ExternalData_add_target target)
if(NOT ExternalData_URL_TEMPLATES)
message(FATAL_ERROR "ExternalData_URL_TEMPLATES is not set!")
endif()
if(NOT ExternalData_OBJECT_STORES)
set(ExternalData_OBJECT_STORES ${CMAKE_BINARY_DIR}/ExternalData/Objects)
endif()
set(config ${CMAKE_CURRENT_BINARY_DIR}/${target}_config.cmake)
configure_file(${_ExternalData_SELF_DIR}/ExternalData_config.cmake.in ${config} @ONLY)
set(files "")
# Set "_ExternalData_FILE_${file}" for each output file to avoid duplicate
# rules. Use local data first to prefer real files over content links.
# Custom commands to copy or link local data.
get_property(data_local GLOBAL PROPERTY _ExternalData_${target}_LOCAL)
foreach(entry IN LISTS data_local)
string(REPLACE "|" ";" tuple "${entry}")
list(GET tuple 0 file)
list(GET tuple 1 name)
if(NOT DEFINED "_ExternalData_FILE_${file}")
set("_ExternalData_FILE_${file}" 1)
add_custom_command(
COMMENT "Generating ${file}"
OUTPUT "${file}"
COMMAND ${CMAKE_COMMAND} -Drelative_top=${CMAKE_BINARY_DIR}
-Dfile=${file} -Dname=${name}
-DExternalData_ACTION=local
-DExternalData_CONFIG=${config}
-P ${_ExternalData_SELF}
DEPENDS "${name}"
)
list(APPEND files "${file}")
endif()
endforeach()
# Custom commands to fetch remote data.
get_property(data_fetch GLOBAL PROPERTY _ExternalData_${target}_FETCH)
foreach(entry IN LISTS data_fetch)
string(REPLACE "|" ";" tuple "${entry}")
list(GET tuple 0 file)
list(GET tuple 1 name)
list(GET tuple 2 ext)
set(stamp "${ext}-stamp")
if(NOT DEFINED "_ExternalData_FILE_${file}")
set("_ExternalData_FILE_${file}" 1)
add_custom_command(
# Users care about the data file, so hide the hash/timestamp file.
COMMENT "Generating ${file}"
# The hash/timestamp file is the output from the build perspective.
# List the real file as a second output in case it is a broken link.
# The files must be listed in this order so CMake can hide from the
# make tool that a symlink target may not be newer than the input.
OUTPUT "${file}${stamp}" "${file}"
# Run the data fetch/update script.
COMMAND ${CMAKE_COMMAND} -Drelative_top=${CMAKE_BINARY_DIR}
-Dfile=${file} -Dname=${name} -Dext=${ext}
-DExternalData_ACTION=fetch
-DExternalData_CONFIG=${config}
-P ${_ExternalData_SELF}
# Update whenever the object hash changes.
DEPENDS "${name}${ext}"
)
list(APPEND files "${file}${stamp}")
endif()
endforeach()
# Custom target to drive all update commands.
add_custom_target(${target} ALL DEPENDS ${files})
endfunction()
function(ExternalData_expand_arguments target outArgsVar)
# Replace DATA{} references with real arguments.
set(data_regex "DATA{([^{}\r\n]*)}")
set(other_regex "([^D]|D[^A]|DA[^T]|DAT[^A]|DATA[^{])+|.")
set(outArgs "")
foreach(arg IN LISTS ARGN)
if("x${arg}" MATCHES "${data_regex}")
# Split argument into DATA{}-pieces and other pieces.
string(REGEX MATCHALL "${data_regex}|${other_regex}" pieces "${arg}")
# Compose output argument with DATA{}-pieces replaced.
set(outArg "")
foreach(piece IN LISTS pieces)
if("x${piece}" MATCHES "^x${data_regex}$")
# Replace this DATA{}-piece with a file path.
string(REGEX REPLACE "${data_regex}" "\\1" data "${piece}")
_ExternalData_arg("${target}" "${piece}" "${data}" file)
set(outArg "${outArg}${file}")
else()
# No replacement needed for this piece.
set(outArg "${outArg}${piece}")
endif()
endforeach()
list(APPEND outArgs "${outArg}")
else()
# No replacements needed in this argument.
list(APPEND outArgs "${arg}")
endif()
endforeach()
set("${outArgsVar}" "${outArgs}" PARENT_SCOPE)
endfunction()
#-----------------------------------------------------------------------------
# Private helper interface
set(_ExternalData_SELF "${CMAKE_CURRENT_LIST_FILE}")
get_filename_component(_ExternalData_SELF_DIR "${_ExternalData_SELF}" PATH)
function(_ExternalData_compute_hash var_hash algo file)
if("${algo}" STREQUAL "MD5")
# TODO: Errors
execute_process(COMMAND "${CMAKE_COMMAND}" -E md5sum "${file}"
OUTPUT_VARIABLE output)
string(SUBSTRING "${output}" 0 32 hash)
set("${var_hash}" "${hash}" PARENT_SCOPE)
else()
# TODO: Other hashes.
message(FATAL_ERROR "Hash algorithm ${algo} unimplemented.")
endif()
endfunction()
function(_ExternalData_random var)
if(NOT ${CMAKE_VERSION} VERSION_LESS 2.8.5)
string(RANDOM LENGTH 6 random)
elseif(EXISTS /dev/urandom)
file(READ /dev/urandom random LIMIT 4 HEX)
else()
message(FATAL_ERROR "CMake >= 2.8.5 required in this environment")
endif()
set("${var}" "${random}" PARENT_SCOPE)
endfunction()
function(_ExternalData_exact_regex regex_var string)
string(REGEX REPLACE "([][+.*()^])" "\\\\\\1" regex "${string}")
set("${regex_var}" "${regex}" PARENT_SCOPE)
endfunction()
function(_ExternalData_atomic_write file content)
_ExternalData_random(random)
set(tmp "${file}.tmp${random}")
file(WRITE "${tmp}" "${content}")
file(RENAME "${tmp}" "${file}")
endfunction()
function(_ExternalData_link_content name var_ext)
if("${ExternalData_LINK_CONTENT}" MATCHES "^(MD5)$")
set(algo "${ExternalData_LINK_CONTENT}")
else()
message(FATAL_ERROR
"Unknown hash algorithm specified by ExternalData_LINK_CONTENT:\n"
" ${ExternalData_LINK_CONTENT}")
endif()
_ExternalData_compute_hash(hash "${algo}" "${name}")
get_filename_component(dir "${name}" PATH)
set(staged "${dir}/.ExternalData_${algo}_${hash}")
set(ext ".md5")
_ExternalData_atomic_write("${name}${ext}" "${hash}\n")
file(RENAME "${name}" "${staged}")
set("${var_ext}" "${ext}" PARENT_SCOPE)
file(RELATIVE_PATH relname "${ExternalData_SOURCE_ROOT}" "${name}${ext}")
message(STATUS "Linked ${relname} to ExternalData ${algo}/${hash}")
endfunction()
function(_ExternalData_arg target arg options var_file)
# Separate data path from the options.
string(REPLACE "," ";" options "${options}")
list(GET options 0 data)
list(REMOVE_AT options 0)
# Convert to full path.
if(IS_ABSOLUTE "${data}")
set(absdata "${data}")
else()
# TODO: If ${data} does not start in "./" or "../" then use search path?
get_filename_component(absdata "${CMAKE_CURRENT_SOURCE_DIR}/${data}" ABSOLUTE)
endif()
# Convert to relative path under the source tree.
if(NOT ExternalData_SOURCE_ROOT)
set(ExternalData_SOURCE_ROOT "${CMAKE_SOURCE_DIR}")
endif()
set(top_src "${ExternalData_SOURCE_ROOT}")
file(RELATIVE_PATH reldata "${top_src}" "${absdata}")
if(IS_ABSOLUTE "${reldata}" OR "${reldata}" MATCHES "^\\.\\./")
message(FATAL_ERROR "Data file referenced by argument\n"
" ${arg}\n"
"does not lie under the top-level source directory\n"
" ${top_src}\n")
endif()
if(NOT ExternalData_BINARY_ROOT)
set(ExternalData_BINARY_ROOT "${CMAKE_BINARY_DIR}")
endif()
set(top_bin "${ExternalData_BINARY_ROOT}")
# Handle in-source builds gracefully.
if("${top_src}" STREQUAL "${top_bin}")
if(ExternalData_LINK_CONTENT)
message(WARNING "ExternalData_LINK_CONTENT cannot be used in-source")
set(ExternalData_LINK_CONTENT 0)
endif()
set(top_same 1)
endif()
set(external "") # Entries external to the source tree.
set(internal "") # Entries internal to the source tree.
set(have_original 0)
# Process options.
set(associated_files "")
set(associated_regex "")
foreach(opt ${options})
if("x${opt}" MATCHES "^xREGEX:[^:/]+$")
# Regular expression to match associated files.
string(REGEX REPLACE "^REGEX:" "" regex "${opt}")
list(APPEND associated_regex "${regex}")
elseif("x${opt}" MATCHES "^[^][:/*?]+$")
# Specific associated file.
list(APPEND associated_files "${opt}")
else()
message(FATAL_ERROR "Unknown option \"${opt}\" in argument\n"
" ${arg}\n")
endif()
endforeach()
if(associated_files OR associated_regex)
# Load the named data file and listed/matching associated files.
_ExternalData_arg_single()
_ExternalData_arg_associated()
elseif("${reldata}" MATCHES "(^|/)[^/.]+$")
# Files with no extension cannot be a series.
_ExternalData_arg_single()
else()
# Match a whole file series by default.
_ExternalData_arg_series()
endif()
if(NOT have_original)
message(FATAL_ERROR "Data file referenced by argument\n"
" ${arg}\n"
"corresponds to source tree path\n"
" ${reldata}\n"
"that does not exist (with or without an extension)!")
endif()
if(external)
# Make the series available in the build tree.
set_property(GLOBAL APPEND PROPERTY
_ExternalData_${target}_FETCH "${external}")
set_property(GLOBAL APPEND PROPERTY
_ExternalData_${target}_LOCAL "${internal}")
set("${var_file}" "${top_bin}/${reldata}" PARENT_SCOPE)
else()
# The whole series is in the source tree.
set("${var_file}" "${top_src}/${reldata}" PARENT_SCOPE)
endif()
endfunction()
macro(_ExternalData_arg_associated)
# Associated files lie in the same directory.
get_filename_component(reldir "${reldata}" PATH)
if(reldir)
set(reldir "${reldir}/")
endif()
_ExternalData_exact_regex(reldir_regex "${reldir}")
# Find files named explicitly.
foreach(file ${associated_files})
_ExternalData_exact_regex(file_regex "${file}")
_ExternalData_arg_find_files("${reldir}${file}" "${reldir_regex}${file_regex}")
endforeach()
# Find files matching the given regular expressions.
set(all "")
set(sep "")
foreach(regex ${associated_regex})
set(all "${all}${sep}${reldir_regex}${regex}")
set(sep "|")
endforeach()
_ExternalData_arg_find_files("${reldir}" "${all}")
endmacro()
macro(_ExternalData_arg_single)
# Match only the named data by itself.
_ExternalData_exact_regex(data_regex "${reldata}")
_ExternalData_arg_find_files("${reldata}" "${data_regex}")
endmacro()
macro(_ExternalData_arg_series)
# Configure series parsing and matching.
if(ExternalData_SERIES_PARSE)
if(NOT "${ExternalData_SERIES_PARSE}" MATCHES
"^\\^\\([^()]*\\)\\([^()]*\\)\\([^()]*\\)\\$$")
message(FATAL_ERROR
"ExternalData_SERIES_PARSE is set to\n"
" ${ExternalData_SERIES_PARSE}\n"
"which is not of the form\n"
" ^(...)(...)(...)$\n")
endif()
set(series_parse "${ExternalData_SERIES_PARSE}")
else()
set(series_parse "^(.*)()(\\.[^./]*)$")
endif()
if(ExternalData_SERIES_MATCH)
set(series_match "${ExternalData_SERIES_MATCH}")
else()
set(series_match "[_.]?[0-9]*")
endif()
# Parse the base, number, and extension components of the series.
string(REGEX REPLACE "${series_parse}" "\\1;\\2;\\3" tuple "${reldata}")
list(LENGTH tuple len)
if(NOT "${len}" EQUAL 3)
message(FATAL_ERROR "Data file referenced by argument\n"
" ${arg}\n"
"corresponds to path\n"
" ${reldata}\n"
"that does not match regular expression\n"
" ${series_parse}")
endif()
list(GET tuple 0 relbase)
list(GET tuple 2 ext)
# Glob files that might match the series.
# Then match match base, number, and extension.
_ExternalData_exact_regex(series_base "${relbase}")
_ExternalData_exact_regex(series_ext "${ext}")
_ExternalData_arg_find_files("${relbase}*${ext}"
"${series_base}${series_match}${series_ext}")
endmacro()
function(_ExternalData_arg_find_files pattern regex)
file(GLOB globbed RELATIVE "${top_src}" "${top_src}/${pattern}*")
foreach(entry IN LISTS globbed)
string(REGEX REPLACE "^(${regex})(\\.md5|)$" "\\1;\\2" tuple "${entry}")
list(LENGTH tuple len)
if("${len}" EQUAL 2)
list(GET tuple 0 relname)
list(GET tuple 1 alg)
set(name "${top_src}/${relname}")
set(file "${top_bin}/${relname}")
if(alg)
list(APPEND external "${file}|${name}|${alg}")
elseif(ExternalData_LINK_CONTENT)
_ExternalData_link_content("${name}" alg)
list(APPEND external "${file}|${name}|${alg}")
elseif(NOT top_same)
list(APPEND internal "${file}|${name}")
endif()
if("${relname}" STREQUAL "${reldata}")
set(have_original 1)
endif()
endif()
endforeach()
set(external "${external}" PARENT_SCOPE)
set(internal "${internal}" PARENT_SCOPE)
set(have_original "${have_original}" PARENT_SCOPE)
endfunction()
#-----------------------------------------------------------------------------
# Private script mode interface
if(CMAKE_GENERATOR OR NOT ExternalData_ACTION)
return()
endif()
if(ExternalData_CONFIG)
include(${ExternalData_CONFIG})
endif()
if(NOT ExternalData_URL_TEMPLATES)
message(FATAL_ERROR "No ExternalData_URL_TEMPLATES set!")
endif()
function(_ExternalData_link_or_copy src dst)
# Create a temporary file first.
get_filename_component(dst_dir "${dst}" PATH)
file(MAKE_DIRECTORY "${dst_dir}")
_ExternalData_random(random)
set(tmp "${dst}.tmp${random}")
if(UNIX)
# Create a symbolic link.
set(tgt "${src}")
if(relative_top)
# Use relative path if files are close enough.
file(RELATIVE_PATH relsrc "${relative_top}" "${src}")
file(RELATIVE_PATH relfile "${relative_top}" "${dst}")
if(NOT IS_ABSOLUTE "${relsrc}" AND NOT "${relsrc}" MATCHES "^\\.\\./" AND
NOT IS_ABSOLUTE "${reldst}" AND NOT "${reldst}" MATCHES "^\\.\\./")
file(RELATIVE_PATH tgt "${dst_dir}" "${src}")
endif()
endif()
execute_process(COMMAND "${CMAKE_COMMAND}" -E create_symlink "${tgt}" "${tmp}" RESULT_VARIABLE result)
else()
# Create a copy.
execute_process(COMMAND "${CMAKE_COMMAND}" -E copy "${src}" "${tmp}" RESULT_VARIABLE result)
endif()
if(result)
file(REMOVE "${tmp}")
message(FATAL_ERROR "Failed to create\n ${tmp}\nfrom\n ${obj}")
endif()
# Atomically create/replace the real destination.
file(RENAME "${tmp}" "${dst}")
endfunction()
function(_ExternalData_download_file url file err_var msg_var)
set(retry 3)
while(retry)
math(EXPR retry "${retry} - 1")
if("${CMAKE_VERSION}" VERSION_GREATER 2.8.4.20110602)
if(ExternalData_TIMEOUT_INACTIVITY)
set(inactivity_timeout INACTIVITY_TIMEOUT ${ExternalData_TIMEOUT_INACTIVITY})
elseif(NOT "${ExternalData_TIMEOUT_INACTIVITY}" EQUAL 0)
set(inactivity_timeout INACTIVITY_TIMEOUT 60)
else()
set(inactivity_timeout "")
endif()
else()
set(inactivity_timeout "")
endif()
if(ExternalData_TIMEOUT_ABSOLUTE)
set(absolute_timeout TIMEOUT ${ExternalData_TIMEOUT_ABSOLUTE})
elseif(NOT "${ExternalData_TIMEOUT_ABSOLUTE}" EQUAL 0)
set(absolute_timeout TIMEOUT 300)
else()
set(absolute_timeout "")
endif()
file(DOWNLOAD "${url}" "${file}" STATUS status LOG log ${inactivity_timeout} ${absolute_timeout} SHOW_PROGRESS)
list(GET status 0 err)
list(GET status 1 msg)
if(err)
if("${msg}" MATCHES "HTTP response code said error" AND
"${log}" MATCHES "error: 503")
set(msg "temporarily unavailable")
endif()
elseif("${log}" MATCHES "\nHTTP[^\n]* 503")
set(err TRUE)
set(msg "temporarily unavailable")
endif()
if(NOT err OR NOT "${msg}" MATCHES "partial|timeout|temporarily")
break()
elseif(retry)
message(STATUS "[download terminated: ${msg}, retries left: ${retry}]")
endif()
endwhile()
set("${err_var}" "${err}" PARENT_SCOPE)
set("${msg_var}" "${msg}" PARENT_SCOPE)
endfunction()
function(_ExternalData_download_object name hash algo var_obj)
# Search all object stores for an existing object.
foreach(dir ${ExternalData_OBJECT_STORES})
set(obj "${dir}/${algo}/${hash}")
if(EXISTS "${obj}")
message(STATUS "Found object: \"${obj}\"")
set("${var_obj}" "${obj}" PARENT_SCOPE)
return()
endif()
endforeach()
# Download object to the first store.
list(GET ExternalData_OBJECT_STORES 0 store)
set(obj "${store}/${algo}/${hash}")
_ExternalData_random(random)
set(tmp "${obj}.tmp${random}")
set(found 0)
set(tried "")
foreach(url_template IN LISTS ExternalData_URL_TEMPLATES)
string(REPLACE "%(hash)" "${hash}" url_tmp "${url_template}")
string(REPLACE "%(algo)" "${algo}" url "${url_tmp}")
message(STATUS "Fetching \"${url}\"")
_ExternalData_download_file("${url}" "${tmp}" err errMsg)
set(tried "${tried}\n ${url}")
if(err)
set(tried "${tried} (${errMsg})")
else()
# Verify downloaded object.
_ExternalData_compute_hash(dl_hash "${algo}" "${tmp}")
if("${dl_hash}" STREQUAL "${hash}")
set(found 1)
break()
else()
set(tried "${tried} (wrong hash ${algo}=${dl_hash})")
if("$ENV{ExternalData_DEBUG_DOWNLOAD}" MATCHES ".")
file(RENAME "${tmp}" "${store}/${algo}/${dl_hash}")
endif()
endif()
endif()
file(REMOVE "${tmp}")
endforeach()
get_filename_component(dir "${name}" PATH)
set(staged "${dir}/.ExternalData_${algo}_${hash}")
if(found)
file(RENAME "${tmp}" "${obj}")
message(STATUS "Downloaded object: \"${obj}\"")
elseif(EXISTS "${staged}")
set(obj "${staged}")
message(STATUS "Staged object: \"${obj}\"")
else()
message(FATAL_ERROR "Object ${algo}=${hash} not found at:${tried}")
endif()
set("${var_obj}" "${obj}" PARENT_SCOPE)
endfunction()
if("${ExternalData_ACTION}" STREQUAL "fetch")
foreach(v ExternalData_OBJECT_STORES file name ext)
if(NOT DEFINED "${v}")
message(FATAL_ERROR "No \"-D${v}=\" value provided!")
endif()
endforeach()
file(READ "${name}${ext}" hash)
string(STRIP "${hash}" hash)
if("${ext}" STREQUAL ".md5")
set(algo "MD5")
else()
message(FATAL_ERROR "Unknown hash algorithm extension \"${ext}\"")
endif()
_ExternalData_download_object("${name}" "${hash}" "${algo}" obj)
# Check if file already corresponds to the object.
set(stamp "${ext}-stamp")
set(file_up_to_date 0)
if(EXISTS "${file}" AND EXISTS "${file}${stamp}")
file(READ "${file}${stamp}" f_hash)
string(STRIP "${f_hash}" f_hash)
if("${f_hash}" STREQUAL "${hash}")
#message(STATUS "File already corresponds to object")
set(file_up_to_date 1)
endif()
endif()
if(file_up_to_date)
# Touch the file to convince the build system it is up to date.
execute_process(COMMAND "${CMAKE_COMMAND}" -E touch "${file}")
else()
_ExternalData_link_or_copy("${obj}" "${file}")
endif()
# Atomically update the hash/timestamp file to record the object referenced.
_ExternalData_atomic_write("${file}${stamp}" "${hash}\n")
elseif("${ExternalData_ACTION}" STREQUAL "local")
foreach(v file name)
if(NOT DEFINED "${v}")
message(FATAL_ERROR "No \"-D${v}=\" value provided!")
endif()
endforeach()
_ExternalData_link_or_copy("${name}" "${file}")
elseif("${ExternalData_ACTION}" STREQUAL "store")
foreach(v dir file)
if(NOT DEFINED "${v}")
message(FATAL_ERROR "No \"-D${v}=\" value provided!")
endif()
endforeach()
if(NOT DEFINED algo)
set(algo "MD5")
endif()
_ExternalData_compute_hash(hash "${algo}" "${file}")
else()
message(FATAL_ERROR "Unknown ExternalData_ACTION=[${ExternalData_ACTION}]")
endif()

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@ -0,0 +1,4 @@
set(ExternalData_OBJECT_STORES "@ExternalData_OBJECT_STORES@")
set(ExternalData_URL_TEMPLATES "@ExternalData_URL_TEMPLATES@")
set(ExternalData_TIMEOUT_INACTIVITY "@ExternalData_TIMEOUT_INACTIVITY@")
set(ExternalData_TIMEOUT_ABSOLUTE "@ExternalData_TIMEOUT_ABSOLUTE@")