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// Copyright 2020 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#pragma once
#include <stddef.h> // for size_t
#include <string> // for string, basic_string
#include <utility> // for move, forward
#include <vector> // for vector
#include "base/Optional.h" // for Optional
#ifdef __APPLE__
#define LIBSUFFIX ".dylib"
#else
#ifdef _WIN32
#include "base/Win32UnicodeString.h"
#define LIBSUFFIX ".dll"
#else
#define LIBSUFFIX ".so"
#endif // !_WIN32 (linux)
#endif // !__APPLE__
namespace android {
namespace base {
// Utility functions to manage file paths. None of these should touch the
// file system. All methods must be static.
class PathUtils {
public:
// An enum listing the supported host file system types.
// HOST_POSIX means a Posix-like file system.
// HOST_WIN32 means a Windows-like file system.
// HOST_TYPE means the current host type (one of the above).
// NOTE: If you update this list, modify kHostTypeCount below too.
enum HostType {
HOST_POSIX = 0,
HOST_WIN32 = 1,
#ifdef _WIN32
HOST_TYPE = HOST_WIN32,
#else
HOST_TYPE = HOST_POSIX,
#endif
};
// The number of distinct items in the HostType enumeration above.
static const int kHostTypeCount = 2;
// Suffixes for an executable file (.exe on Windows, empty otherwise)
static const char* const kExeNameSuffixes[kHostTypeCount];
// Suffixe for an executable file on the current platform
static const char* const kExeNameSuffix;
// Returns the executable name for a base name |baseName|
static std::string toExecutableName(const char* baseName, HostType hostType);
static std::string toExecutableName(const char* baseName) {
return toExecutableName(baseName, HOST_TYPE);
}
// Return true if |ch| is a directory separator for a given |hostType|.
static bool isDirSeparator(int ch, HostType hostType);
// Return true if |ch| is a directory separator for the current platform.
static bool isDirSeparator(int ch) {
return isDirSeparator(ch, HOST_TYPE);
}
// Return true if |ch| is a path separator for a given |hostType|.
static bool isPathSeparator(int ch, HostType hostType);
// Return true if |ch| is a path separator for the current platform.
static bool isPathSeparator(int ch) {
return isPathSeparator(ch, HOST_TYPE);
}
// Return the directory separator character for a given |hostType|
static char getDirSeparator(HostType hostType) {
return (hostType == HOST_WIN32) ? '\\' : '/';
}
// Remove trailing separators from a |path| string, for a given |hostType|.
static std::string removeTrailingDirSeparator(const char* path,
HostType hostType);
// Remove trailing separators from a |path| string for the current host.
static std::string removeTrailingDirSeparator(const char* path) {
return removeTrailingDirSeparator(path, HOST_TYPE);
}
// Add a trailing separator if needed.
static std::string addTrailingDirSeparator(const std::string& path,
HostType hostType);
static std::string addTrailingDirSeparator(const char* path,
HostType hostType);
// Add a trailing separator if needed.
static std::string addTrailingDirSeparator(const std::string& path) {
return addTrailingDirSeparator(path, HOST_TYPE);
}
// If |path| starts with a root prefix, return its size in bytes, or
// 0 otherwise. The definition of valid root prefixes depends on the
// value of |hostType|. For HOST_POSIX, it's any path that begins
// with a slash (/). For HOST_WIN32, the following prefixes are
// recognized:
// <drive>:
// <drive>:<sep>
// <sep><sep>volumeName<sep>
static size_t rootPrefixSize(const std::string& path, HostType hostType);
// Return the root prefix for the current platform. See above for
// documentation.
static size_t rootPrefixSize(const char* path) {
return rootPrefixSize(path, HOST_TYPE);
}
// Return true iff |path| is an absolute path for a given |hostType|.
static bool isAbsolute(const char* path, HostType hostType);
// Return true iff |path| is an absolute path for the current host.
static bool isAbsolute(const char* path) {
return isAbsolute(path, HOST_TYPE);
}
// Split |path| into a directory name and a file name. |dirName| and
// |baseName| are optional pointers to strings that will receive the
// corresponding components on success. |hostType| is a host type.
// Return true on success, or false on failure.
// Note that unlike the Unix 'basename' command, the command will fail
// if |path| ends with directory separator or is a single root prefix.
// Windows root prefixes are fully supported, which means the following:
//
// / -> error.
// /foo -> '/' + 'foo'
// foo -> '.' + 'foo'
// <drive>: -> error.
// <drive>:foo -> '<drive>:' + 'foo'
// <drive>:\foo -> '<drive>:\' + 'foo'
//
static bool split(const char* path,
HostType hostType,
const char** dirName,
const char** baseName);
// A variant of split() for the current process' host type.
static bool split(const char* path,
const char** dirName,
const char** baseName) {
return split(path, HOST_TYPE, dirName, baseName);
}
// Join two path components together. Note that if |path2| is an
// absolute path, this function returns a copy of |path2|, otherwise
// the result will be the concatenation of |path1| and |path2|, if
// |path1| doesn't end with a directory separator, a |hostType| specific
// one will be inserted between the two paths in the result.
static std::string join(const std::string& path1,
const std::string& path2,
HostType hostType);
// A variant of join() for the current process' host type.
static std::string join(const std::string& path1, const std::string& path2) {
return join(path1, path2, HOST_TYPE);
}
// A convenience function to join a bunch of paths at once
template <class... Paths>
static std::string join(const std::string& path1,
const std::string& path2,
Paths&&... paths) {
return join(path1, join(path2, std::forward<Paths>(paths)...));
}
// Decompose |path| into individual components. If |path| has a root
// prefix, it will always be the first component. I.e. for Posix
// systems this will be '/' (for absolute paths). For Win32 systems,
// it could be 'C:" (for a path relative to a root volume) or "C:\"
// for an absolute path from volume C).,
// On success, return true and sets |out| to a vector of strings,
// each one being a path component (prefix or subdirectory or file
// name). Directory separators do not appear in components, except
// for the root prefix, if any.
static std::vector<std::string> decompose(std::string&& path,
HostType hostType);
static std::vector<std::string> decompose(const std::string& path,
HostType hostType);
template <class String>
static std::vector<String> decompose(const String& path,
HostType hostType);
// Decompose |path| into individual components for the host platform.
// See comments above for more details.
static std::vector<std::string> decompose(std::string&& path) {
return decompose(std::move(path), HOST_TYPE);
}
static std::vector<std::string> decompose(const std::string& path) {
return decompose(path, HOST_TYPE);
}
// Recompose a path from individual components into a file path string.
// |components| is a vector of strings, and |hostType| the target
// host type to use. Return a new file path string. Note that if the
// first component is a root prefix, it will be kept as is, i.e.:
// [ 'C:', 'foo' ] -> 'C:foo' on Win32, but not Posix where it will
// be 'C:/foo'.
static std::string recompose(const std::vector<std::string>& components,
HostType hostType);
template <class String>
static std::string recompose(const std::vector<String>& components,
HostType hostType);
// Recompose a path from individual components into a file path string
// for the current host. |components| is a vector os strings.
// Returns a new file path string.
template <class String>
static std::string recompose(const std::vector<String>& components) {
return PathUtils::recompose(components, HOST_TYPE);
}
// Given a list of components returned by decompose(), simplify it
// by removing instances of '.' and '..' when that makes sense.
// Note that it is not possible to simplify initial instances of
// '..', i.e. "foo/../../bar" -> "../bar"
static void simplifyComponents(std::vector<std::string>* components);
template <class String>
static void simplifyComponents(std::vector<String>* components);
// Returns a version of |path| that is relative to |base|.
// This can be useful for converting absolute paths to
// relative paths given |base|.
// Example:
// |base|: C:\Users\foo
// |path|: C:\Users\foo\AppData\Local\Android\Sdk
// would give
// AppData\Local\Android\Sdk.
// If |base| is not a prefix of |path|, fails by returning
// the original |path| unmodified.
static std::string relativeTo(const char* base, const char* path, HostType hostType);
static std::string relativeTo(const char* base, const char* path) {
return relativeTo(base, path, HOST_TYPE);
}
static Optional<std::string> pathWithoutDirs(const char* name);
static Optional<std::string> pathToDir(const char* name);
// Replaces the entries ${xx} with the value of the environment variable
// xx if it exists. Returns kNullopt if the environment variable is
// not set or empty.
static Optional<std::string> pathWithEnvSubstituted(const char* path);
// Replaces the entries ${xx} with the value of the environment variable
// xx if it exists. Returns kNullopt if the environment variable is
// not set or empty.
static Optional<std::string> pathWithEnvSubstituted(std::vector<std::string> decomposedPath);
#ifdef _WIN32
static Win32UnicodeString asUnicodePath(const char* path) { return Win32UnicodeString(path); }
#else
static std::string asUnicodePath(const char* path) { return path; }
#endif
};
// Useful shortcuts to avoid too much typing.
static const PathUtils::HostType kHostPosix = PathUtils::HOST_POSIX;
static const PathUtils::HostType kHostWin32 = PathUtils::HOST_WIN32;
static const PathUtils::HostType kHostType = PathUtils::HOST_TYPE;
template <class... Paths>
std::string pj(const std::string& path1,
const std::string& path2,
Paths&&... paths) {
return PathUtils::join(path1,
pj(path2, std::forward<Paths>(paths)...));
}
std::string pj(const std::string& path1, const std::string& path2);
std::string pj(const std::vector<std::string>& paths);
bool pathExists(const char* path);
} // namespace base
} // namespace android