available_compressed.jl

function read_version{T <: AbstractString}(s::Vector{T}, i::Int)
    version = s[i]; i += 1
    # @assert ismatch(Base.VERSION_REGEX, version)
    i += 1 # skip "-----" under the version
    sha = s[i]; i += 1
    requires = String[]
    while i <= length(s) && !isempty(s[i])
        push!(requires, s[i]); i += 1
    end
    i += 1 # skip the empty string
    return version, sha, requires, i
end

function available(repo::GitRepo)
    pkgs = Dict{String,Dict{VersionNumber,Available}}()
    head = LibGit2.head(repo)
    ht = LibGit2.peel(LibGit2.GitTree, head)
    for first_letter_tree in ht # A, B, C folders...
        !isdir(first_letter_tree) && continue
        first_letter_name = filename(first_letter_tree)
        startswith(first_letter_name, '.') && continue
        for pkg_entry in peel(GitTree, object(repo, first_letter_tree))
            pkg_name = filename(pkg_entry)
            (!endswith(pkg_name, ".versions") || !isfile(pkg_entry)) && continue
            pkg_name = split(pkg_name, ".version")[1]
            blob = peel(GitBlob, object(repo, pkg_entry))
            file_lines = split(unsafe_string(convert(Cstring, content(blob))), '\n')
            i = 3 # Skip url + empty line
            isempty(file_lines[i]) && continue # TODO: Package is without a version
            while i <= length(file_lines)
                ver, sha, requires, i = read_version(file_lines, i)
                haskey(pkgs, pkg_name) || (pkgs[pkg_name] = Dict{VersionNumber,Available}())
                pkgs[pkg_name][convert(VersionNumber, ver)] = Available(sha, Reqs.parse(requires))
            end
        end
    end
    return pkgs
end