/// <summary>
/// Helper function to determine the model version that is being loaded.
/// </summary>
private static bool CheckModelVersion(ModelLoadContext ctx, VersionInfo versionInfo)
{
try
{
ctx.CheckVersionInfo(versionInfo);
return(true);
}
catch (Exception)
{
//consume
return(false);
}
}
public static FeatureNameCollection Create(ModelLoadContext ctx)
{
Contracts.AssertValue(ctx);
ctx.CheckAtModel();
ctx.CheckVersionInfo(GetVersionInfo());
// *** Binary format ***
// int: number of features (size)
// int: number of indices (0 if dense)
// int[]: indices (if sparse)
// int[]: ids of names (matches either number of features or number of indices
var size = ctx.Reader.ReadInt32();
Contracts.CheckDecode(size >= 0);
var isize = ctx.Reader.ReadInt32();
Contracts.CheckDecode(isize >= -1);
if (isize < 0)
{
// Dense case
var names = new string[size];
for (int i = 0; i < size; i++)
{
var name = ctx.LoadStringOrNull();
names[i] = string.IsNullOrEmpty(name) ? null : name;
}
return(Create(size, names));
}
var dict = new Dictionary <int, string>();
var indices = new int[isize];
var prev = -1;
for (int ii = 0; ii < isize; ii++)
{
indices[ii] = ctx.Reader.ReadInt32();
Contracts.CheckDecode(prev < indices[ii]);
prev = indices[ii];
}
Contracts.CheckDecode(prev < size);
for (int ii = 0; ii < isize; ii++)
{
var name = ctx.LoadStringOrNull();
if (!string.IsNullOrEmpty(name))
{
dict.Add(indices[ii], name);
}
}
return(Create(size, dict));
}
