[lldb] [NFC] Remove min pkt size for compression setting (#81075)
debugserver will not compress small packets; the overhead of the
compression header makes this useful for larger packets. I default to
384 bytes in debugserver, and added an option for lldb to request a
different cutoff. This option has never been used in lldb in the past
nine years, so I don't think there's any point to keeping it around.
diff --git a/lldb/docs/lldb-gdb-remote.txt b/lldb/docs/lldb-gdb-remote.txt
index 76ac3f2..6c29de6 100644
--- a/lldb/docs/lldb-gdb-remote.txt
+++ b/lldb/docs/lldb-gdb-remote.txt
@@ -1998,16 +1998,12 @@
// If the debug stub can support compression, it indictes this in the reply of the
// "qSupported" packet. e.g.
// LLDB SENDS: qSupported:xmlRegisters=i386,arm,mips
-// STUB REPLIES: qXfer:features:read+;SupportedCompressions=lzfse,zlib-deflate,lz4,lzma;DefaultCompressionMinSize=384
+// STUB REPLIES: qXfer:features:read+;SupportedCompressions=lzfse,zlib-deflate,lz4,lzma;
//
// If lldb knows how to use any of these compression algorithms, it can ask that this
-// compression mode be enabled. It may optionally change the minimum packet size
-// where compression is used. Typically small packets do not benefit from compression,
-// as well as compression headers -- compression is most beneficial with larger packets.
+// compression mode be enabled.
//
// QEnableCompression:type:zlib-deflate;
-// or
-// QEnableCompression:type:zlib-deflate;minsize:512;
//
// The debug stub should reply with an uncompressed "OK" packet to indicate that the
// request was accepted. All further packets the stub sends will use this compression.
diff --git a/lldb/tools/debugserver/source/RNBRemote.cpp b/lldb/tools/debugserver/source/RNBRemote.cpp
index 2038492..feea4c9 100644
--- a/lldb/tools/debugserver/source/RNBRemote.cpp
+++ b/lldb/tools/debugserver/source/RNBRemote.cpp
@@ -3575,8 +3575,6 @@
if (enable_compression) {
reply << "SupportedCompressions=lzfse,zlib-deflate,lz4,lzma;";
- reply << "DefaultCompressionMinSize=" << std::dec << m_compression_minsize
- << ";";
}
#if (defined(__arm64__) || defined(__aarch64__))
@@ -4482,46 +4480,25 @@
return SendPacket("OK");
}
-// QEnableCompression:type:<COMPRESSION-TYPE>;minsize:<MINIMUM PACKET SIZE TO
-// COMPRESS>;
+// QEnableCompression:type:<COMPRESSION-TYPE>;
//
// type: must be a type previously reported by the qXfer:features:
// SupportedCompressions list
-//
-// minsize: is optional; by default the qXfer:features:
-// DefaultCompressionMinSize value is used
-// debugserver may have a better idea of what a good minimum packet size to
-// compress is than lldb.
rnb_err_t RNBRemote::HandlePacket_QEnableCompression(const char *p) {
p += sizeof("QEnableCompression:") - 1;
- size_t new_compression_minsize = m_compression_minsize;
- const char *new_compression_minsize_str = strstr(p, "minsize:");
- if (new_compression_minsize_str) {
- new_compression_minsize_str += strlen("minsize:");
- errno = 0;
- new_compression_minsize = strtoul(new_compression_minsize_str, NULL, 10);
- if (errno != 0 || new_compression_minsize == ULONG_MAX) {
- new_compression_minsize = m_compression_minsize;
- }
- }
-
if (strstr(p, "type:zlib-deflate;") != nullptr) {
EnableCompressionNextSendPacket(compression_types::zlib_deflate);
- m_compression_minsize = new_compression_minsize;
return SendPacket("OK");
} else if (strstr(p, "type:lz4;") != nullptr) {
EnableCompressionNextSendPacket(compression_types::lz4);
- m_compression_minsize = new_compression_minsize;
return SendPacket("OK");
} else if (strstr(p, "type:lzma;") != nullptr) {
EnableCompressionNextSendPacket(compression_types::lzma);
- m_compression_minsize = new_compression_minsize;
return SendPacket("OK");
} else if (strstr(p, "type:lzfse;") != nullptr) {
EnableCompressionNextSendPacket(compression_types::lzfse);
- m_compression_minsize = new_compression_minsize;
return SendPacket("OK");
}
