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Updated a few more Host::File functions and added documentation. 

llvm-svn: 125110
This commit is contained in:
Greg Clayton 2011-02-08 19:54:44 +00:00
parent 4d83c691f6
commit 846b64bf83
2 changed files with 232 additions and 8 deletions
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183
lldb/include/lldb/Host/File.h
View File

@ -12,7 +12,6 @@
#if defined(__cplusplus)
#include "lldb/lldb-private.h"
#include "lldb/Host/FileSpec.h"
namespace lldb_private {
@ -62,18 +61,18 @@ public:
///
/// Takes a path to a file which can be just a filename, or a full
/// path. If \a path is not NULL or empty, this function will call
/// FileSpec::SetFile (const char *path, bool resolve).
/// File::Open (const char *path, uint32_t options, uint32_t permissions).
///
/// @param[in] path
/// The full or partial path to a file.
///
/// @param[in] options
/// Options to use when opening (see OpenOptions)
/// Options to use when opening (see File::OpenOptions)
///
/// @param[in] permissions
/// Options to use when opening (see OpenOptions)
/// Options to use when opening (see File::Permissions)
///
/// @see FileSpec::SetFile (const char *path, bool resolve)
/// @see File::Open (const char *path, uint32_t options, uint32_t permissions)
//------------------------------------------------------------------
File (const char *path,
uint32_t options,
@ -146,6 +145,21 @@ public:
Error
GetFileSpec (FileSpec &file_spec) const;
//------------------------------------------------------------------
/// Open a file for read/writing with the specified options.
///
/// Takes a path to a file which can be just a filename, or a full
/// path.
///
/// @param[in] path
/// The full or partial path to a file.
///
/// @param[in] options
/// Options to use when opening (see File::OpenOptions)
///
/// @param[in] permissions
/// Options to use when opening (see File::Permissions)
//------------------------------------------------------------------
Error
Open (const char *path,
uint32_t options,
@ -154,21 +168,174 @@ public:
Error
Close ();
//------------------------------------------------------------------
/// Read bytes from a file from the current file position.
///
/// NOTE: This function is NOT thread safe. Use the read function
/// that takes an "off_t &offset" to ensure correct operation in
/// multi-threaded environments.
///
/// @param[in] buf
/// A buffer where to put the bytes that are read.
///
/// @param[in/out] num_bytes
/// The number of bytes to read form the current file position
/// which gets modified with the number of bytes that were read.
///
/// @return
/// An error object that indicates success or the reason for
/// failure.
//------------------------------------------------------------------
Error
Read (void *dst, size_t &num_bytes);
Read (void *buf, size_t &num_bytes);
//------------------------------------------------------------------
/// Write bytes to a file at the current file position.
///
/// NOTE: This function is NOT thread safe. Use the write function
/// that takes an "off_t &offset" to ensure correct operation in
/// multi-threaded environments.
///
/// @param[in] buf
/// A buffer where to put the bytes that are read.
///
/// @param[in/out] num_bytes
/// The number of bytes to write to the current file position
/// which gets modified with the number of bytes that were
/// written.
///
/// @return
/// An error object that indicates success or the reason for
/// failure.
//------------------------------------------------------------------
Error
Write (const void *src, size_t &num_bytes);
Write (const void *buf, size_t &num_bytes);
//------------------------------------------------------------------
/// Seek to an offset relative to the beginning of the file.
///
/// NOTE: This function is NOT thread safe, other threads that
/// access this object might also change the current file position.
/// For thread safe reads and writes see the following functions:
/// @see File::Read (void *, size_t, off_t &)
/// @see File::Write (const void *, size_t, off_t &)
///
/// @param[in/out] offset
/// The offset to seek to within the file relative to the
/// beginning of the file which gets filled in the the resulting
/// absolute file offset.
///
/// @return
/// An error object that indicates success or the reason for
/// failure.
//------------------------------------------------------------------
Error
SeekFromStart (off_t& offset);
//------------------------------------------------------------------
/// Seek to an offset relative to the current file position.
///
/// NOTE: This function is NOT thread safe, other threads that
/// access this object might also change the current file position.
/// For thread safe reads and writes see the following functions:
/// @see File::Read (void *, size_t, off_t &)
/// @see File::Write (const void *, size_t, off_t &)
///
/// @param[in/out] offset
/// The offset to seek to within the file relative to the
/// current file position. On return this parameter gets filled
/// in the the resulting absolute file offset.
///
/// @return
/// An error object that indicates success or the reason for
/// failure.
//------------------------------------------------------------------
Error
SeekFromCurrent (off_t& offset);
//------------------------------------------------------------------
/// Seek to an offset relative to the end of the file.
///
/// NOTE: This function is NOT thread safe, other threads that
/// access this object might also change the current file position.
/// For thread safe reads and writes see the following functions:
/// @see File::Read (void *, size_t, off_t &)
/// @see File::Write (const void *, size_t, off_t &)
///
/// @param[in/out] offset
/// The offset to seek to within the file relative to the
/// end of the file which gets filled in the the resulting
/// absolute file offset.
///
/// @return
/// An error object that indicates success or the reason for
/// failure.
//------------------------------------------------------------------
Error
SeekFromEnd (off_t& offset);
//------------------------------------------------------------------
/// Read bytes from a file from the specified file offset.
///
/// NOTE: This function is thread safe in that clients manager their
/// own file position markers and reads on other threads won't mess
/// up the current read.
///
/// @param[in] buf
/// A buffer where to put the bytes that are read.
///
/// @param[in/out] num_bytes
/// The number of bytes to read form the current file position
/// which gets modified with the number of bytes that were read.
///
/// @param[in/out] offset
/// The offset within the file from which to read \a num_bytes
/// bytes. This offset gets incremented by the number of bytes
/// that were read.
///
/// @return
/// An error object that indicates success or the reason for
/// failure.
//------------------------------------------------------------------
Error
Read (void *dst, size_t &num_bytes, off_t &offset);
//------------------------------------------------------------------
/// Write bytes to a file at the specified file offset.
///
/// NOTE: This function is thread safe in that clients manager their
/// own file position markers, though clients will need to implement
/// their own locking externally to avoid multiple people writing
/// to the file at the same time.
///
/// @param[in] buf
/// A buffer containing the bytes to write.
///
/// @param[in/out] num_bytes
/// The number of bytes to write to the file at offset \a offset.
/// \a num_bytes gets modified with the number of bytes that
/// were read.
///
/// @param[in/out] offset
/// The offset within the file at which to write \a num_bytes
/// bytes. This offset gets incremented by the number of bytes
/// that were written.
///
/// @return
/// An error object that indicates success or the reason for
/// failure.
//------------------------------------------------------------------
Error
Write (const void *src, size_t &num_bytes, off_t &offset);
//------------------------------------------------------------------
/// Sync to disk.
///
/// @return
/// An error object that indicates success or the reason for
/// failure.
//------------------------------------------------------------------
Error
Sync ();
@ -182,4 +349,4 @@ protected:
} // namespace lldb_private
#endif // #if defined(__cplusplus)
#endif // liblldb_FileSpec_h_
#endif // liblldb_File_h_

57
lldb/source/Host/common/File.cpp
View File

@ -13,6 +13,7 @@
#include <fcntl.h>
#include "lldb/Core/Error.h"
#include "lldb/Host/FileSpec.h"
using namespace lldb;
using namespace lldb_private;
@ -186,6 +187,7 @@ File::Sync ()
}
return error;
}
Error
File::Read (void *buf, size_t &num_bytes)
{
@ -232,3 +234,58 @@ File::Write (const void *buf, size_t &num_bytes)
return error;
}
Error
File::Read (void *buf, size_t &num_bytes, off_t &offset)
{
Error error;
if (IsValid ())
{
ssize_t bytes_read = ::pread (m_file_desc, buf, num_bytes, offset);
if (bytes_read < 0)
{
num_bytes = 0;
error.SetErrorToErrno();
}
else
{
offset += bytes_read;
num_bytes = bytes_read;
}
}
else
{
num_bytes = 0;
error.SetErrorString("invalid file handle");
}
return error;
}
Error
File::Write (const void *buf, size_t &num_bytes, off_t &offset)
{
Error error;
if (IsValid())
{
ssize_t bytes_written = ::pwrite (m_file_desc, buf, num_bytes, offset);
if (bytes_written < 0)
{
num_bytes = 0;
error.SetErrorToErrno();
}
else
{
offset += bytes_written;
num_bytes = bytes_written;
}
}
else
{
num_bytes = 0;
error.SetErrorString("invalid file handle");
}
return error;
}