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package azblob
import (
"net"
"net/url"
"strings"
)
const (
snapshot = "snapshot"
versionId = "versionid"
SnapshotTimeFormat = "2006-01-02T15:04:05.0000000Z07:00"
)
// A BlobURLParts object represents the components that make up an Azure Storage Container/Blob URL. You parse an
// existing URL into its parts by calling NewBlobURLParts(). You construct a URL from parts by calling URL().
// NOTE: Changing any SAS-related field requires computing a new SAS signature.
type BlobURLParts struct {
Scheme string // Ex: "https://"
Host string // Ex: "account.blob.core.windows.net", "10.132.141.33", "10.132.141.33:80"
IPEndpointStyleInfo IPEndpointStyleInfo
ContainerName string // "" if no container
BlobName string // "" if no blob
Snapshot string // "" if not a snapshot
SAS SASQueryParameters
UnparsedParams string
VersionID string // "" if not versioning enabled
}
// IPEndpointStyleInfo is used for IP endpoint style URL when working with Azure storage emulator.
// Ex: "https://10.132.141.33/accountname/containername"
type IPEndpointStyleInfo struct {
AccountName string // "" if not using IP endpoint style
}
// isIPEndpointStyle checkes if URL's host is IP, in this case the storage account endpoint will be composed as:
// http(s)://IP(:port)/storageaccount/container/...
// As url's Host property, host could be both host or host:port
func isIPEndpointStyle(host string) bool {
if host == "" {
return false
}
if h, _, err := net.SplitHostPort(host); err == nil {
host = h
}
// For IPv6, there could be case where SplitHostPort fails for cannot finding port.
// In this case, eliminate the '[' and ']' in the URL.
// For details about IPv6 URL, please refer to https://tools.ietf.org/html/rfc2732
if host[0] == '[' && host[len(host)-1] == ']' {
host = host[1 : len(host)-1]
}
return net.ParseIP(host) != nil
}
// NewBlobURLParts parses a URL initializing BlobURLParts' fields including any SAS-related & snapshot query parameters. Any other
// query parameters remain in the UnparsedParams field. This method overwrites all fields in the BlobURLParts object.
func NewBlobURLParts(u url.URL) BlobURLParts {
up := BlobURLParts{
Scheme: u.Scheme,
Host: u.Host,
}
// Find the container & blob names (if any)
if u.Path != "" {
path := u.Path
if path[0] == '/' {
path = path[1:] // If path starts with a slash, remove it
}
if isIPEndpointStyle(up.Host) {
if accountEndIndex := strings.Index(path, "/"); accountEndIndex == -1 { // Slash not found; path has account name & no container name or blob
up.IPEndpointStyleInfo.AccountName = path
path = "" // No ContainerName present in the URL so path should be empty
} else {
up.IPEndpointStyleInfo.AccountName = path[:accountEndIndex] // The account name is the part between the slashes
path = path[accountEndIndex+1:] // path refers to portion after the account name now (container & blob names)
}
}
containerEndIndex := strings.Index(path, "/") // Find the next slash (if it exists)
if containerEndIndex == -1 { // Slash not found; path has container name & no blob name
up.ContainerName = path
} else {
up.ContainerName = path[:containerEndIndex] // The container name is the part between the slashes
up.BlobName = path[containerEndIndex+1:] // The blob name is after the container slash
}
}
// Convert the query parameters to a case-sensitive map & trim whitespace
paramsMap := u.Query()
up.Snapshot = "" // Assume no snapshot
up.VersionID = "" // Assume no versionID
if snapshotStr, ok := caseInsensitiveValues(paramsMap).Get(snapshot); ok {
up.Snapshot = snapshotStr[0]
// If we recognized the query parameter, remove it from the map
delete(paramsMap, snapshot)
}
if versionIDs, ok := caseInsensitiveValues(paramsMap).Get(versionId); ok {
up.VersionID = versionIDs[0]
// If we recognized the query parameter, remove it from the map
delete(paramsMap, versionId) // delete "versionid" from paramsMap
delete(paramsMap, "versionId") // delete "versionId" from paramsMap
}
up.SAS = newSASQueryParameters(paramsMap, true)
up.UnparsedParams = paramsMap.Encode()
return up
}
type caseInsensitiveValues url.Values // map[string][]string
func (values caseInsensitiveValues) Get(key string) ([]string, bool) {
key = strings.ToLower(key)
for k, v := range values {
if strings.ToLower(k) == key {
return v, true
}
}
return []string{}, false
}
// URL returns a URL object whose fields are initialized from the BlobURLParts fields. The URL's RawQuery
// field contains the SAS, snapshot, and unparsed query parameters.
func (up BlobURLParts) URL() url.URL {
path := ""
if isIPEndpointStyle(up.Host) && up.IPEndpointStyleInfo.AccountName != "" {
path += "/" + up.IPEndpointStyleInfo.AccountName
}
// Concatenate container & blob names (if they exist)
if up.ContainerName != "" {
path += "/" + up.ContainerName
if up.BlobName != "" {
path += "/" + up.BlobName
}
}
rawQuery := up.UnparsedParams
//If no snapshot is initially provided, fill it in from the SAS query properties to help the user
if up.Snapshot == "" && !up.SAS.snapshotTime.IsZero() {
up.Snapshot = up.SAS.snapshotTime.Format(SnapshotTimeFormat)
}
// Concatenate blob snapshot query parameter (if it exists)
if up.Snapshot != "" {
if len(rawQuery) > 0 {
rawQuery += "&"
}
rawQuery += snapshot + "=" + up.Snapshot
}
// Concatenate blob version id query parameter (if it exists)
if up.VersionID != "" {
if len(rawQuery) > 0 {
rawQuery += "&"
}
rawQuery += versionId + "=" + up.VersionID
}
sas := up.SAS.Encode()
if sas != "" {
if len(rawQuery) > 0 {
rawQuery += "&"
}
rawQuery += sas
}
u := url.URL{
Scheme: up.Scheme,
Host: up.Host,
Path: path,
RawQuery: rawQuery,
}
return u
}
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