Full backup tweaks
* provide placeholder UI showing backup/restore start/stop/timeout
* don't kill the progress UI in mid stream
* tidy up the pax extended header data writing a little
Change-Id: Ife0cb78e3facb541d8327f1d5ca5fe77faa6cbca
diff --git a/libs/utils/BackupHelpers.cpp b/libs/utils/BackupHelpers.cpp
index cfb013e..e15875f 100644
--- a/libs/utils/BackupHelpers.cpp
+++ b/libs/utils/BackupHelpers.cpp
@@ -468,6 +468,19 @@
sprintf(buf + 148, "%06o", sum); // the trailing space is already in place
}
+// Returns number of bytes written
+static int write_pax_header_entry(char* buf, const char* key, const char* value) {
+ // start with the size of "1 key=value\n"
+ int len = strlen(key) + strlen(value) + 4;
+ if (len > 9) len++;
+ if (len > 99) len++;
+ if (len > 999) len++;
+ // since PATH_MAX is 4096 we don't expect to have to generate any single
+ // header entry longer than 9999 characters
+
+ return sprintf(buf, "%d %s=%s\n", len, key, value);
+}
+
int write_tarfile(const String8& packageName, const String8& domain,
const String8& rootpath, const String8& filepath, BackupDataWriter* writer)
{
@@ -525,8 +538,7 @@
}
// Good to go -- first construct the standard tar header at the start of the buffer
- memset(buf, 0, 512); // tar header is 512 bytes
- memset(paxHeader, 0, 512);
+ memset(buf, 0, BUFSIZE);
// Magic fields for the ustar file format
strcat(buf + 257, "ustar");
@@ -602,24 +614,20 @@
// If we're using a pax extended header, build & write that here; lengths are
// already preflighted
if (needExtended) {
+ char sizeStr[32]; // big enough for a 64-bit unsigned value in decimal
+ char* p = paxData;
+
// construct the pax extended header data block
memset(paxData, 0, BUFSIZE - (paxData - buf));
- char* p = paxData;
int len;
// size header -- calc len in digits by actually rendering the number
// to a string - brute force but simple
- len = sprintf(p, "%lld", s.st_size) + 8; // 8 for "1 size=" and final LF
- if (len >= 10) len++;
-
- memset(p, 0, 512);
- p += sprintf(p, "%d size=%lld\n", len, s.st_size);
+ snprintf(sizeStr, sizeof(sizeStr), "%lld", s.st_size);
+ p += write_pax_header_entry(p, "size", sizeStr);
// fullname was generated above with the ustar paths
- len = fullname.length() + 8; // 8 for "1 path=" and final LF
- if (len >= 10) len++;
- if (len >= 100) len++;
- p += sprintf(p, "%d path=%s\n", len, fullname.string());
+ p += write_pax_header_entry(p, "path", fullname.string());
// Now we know how big the pax data is
int paxLen = p - paxData;