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git/sideband.c

278 lines
6.6 KiB

#include "cache.h"
sideband: highlight keywords in remote sideband output The colorization is controlled with the config setting "color.remote". Supported keywords are "error", "warning", "hint" and "success". They are highlighted if they appear at the start of the line, which is common in error messages, eg. ERROR: commit is missing Change-Id The Git push process itself prints lots of non-actionable messages (eg. bandwidth statistics, object counters for different phases of the process). This obscures actionable error messages that servers may send back. Highlighting keywords in the sideband draws more attention to those messages. The background for this change is that Gerrit does server-side processing to create or update code reviews, and actionable error messages (eg. missing Change-Id) must be communicated back to the user during the push. User research has shown that new users have trouble seeing these messages. The highlighting is done on the client rather than server side, so servers don't have to grow capabilities to understand terminal escape codes and terminal state. It also consistent with the current state where Git is control of the local display (eg. prefixing messages with "remote: "). The highlighting can be configured using color.remote.<KEYWORD> configuration settings. Since the keys are matched case insensitively, we match the keywords case insensitively too. Finally, this solution is backwards compatible: many servers already prefix their messages with "error", and they will benefit from this change without requiring a server update. By contrast, a server-side solution would likely require plumbing the TERM variable through the git protocol, so it would require changes to both server and client. Helped-by: Duy Nguyen <pclouds@gmail.com> Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
4 years ago
#include "color.h"
#include "config.h"
#include "sideband.h"
sideband: highlight keywords in remote sideband output The colorization is controlled with the config setting "color.remote". Supported keywords are "error", "warning", "hint" and "success". They are highlighted if they appear at the start of the line, which is common in error messages, eg. ERROR: commit is missing Change-Id The Git push process itself prints lots of non-actionable messages (eg. bandwidth statistics, object counters for different phases of the process). This obscures actionable error messages that servers may send back. Highlighting keywords in the sideband draws more attention to those messages. The background for this change is that Gerrit does server-side processing to create or update code reviews, and actionable error messages (eg. missing Change-Id) must be communicated back to the user during the push. User research has shown that new users have trouble seeing these messages. The highlighting is done on the client rather than server side, so servers don't have to grow capabilities to understand terminal escape codes and terminal state. It also consistent with the current state where Git is control of the local display (eg. prefixing messages with "remote: "). The highlighting can be configured using color.remote.<KEYWORD> configuration settings. Since the keys are matched case insensitively, we match the keywords case insensitively too. Finally, this solution is backwards compatible: many servers already prefix their messages with "error", and they will benefit from this change without requiring a server update. By contrast, a server-side solution would likely require plumbing the TERM variable through the git protocol, so it would require changes to both server and client. Helped-by: Duy Nguyen <pclouds@gmail.com> Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
4 years ago
#include "help.h"
sideband: diagnose more sideband anomalies In demultiplex_sideband(), there are two oddities when we check an incoming packet: - if it has zero length, then we assume it's a flush packet. This means we fail to notice the difference between a real flush and a true zero-length packet that's missing its sideband designator. It's not a huge problem in practice because we'd never send a zero-length data packet (even our keepalives are otherwise-empty sideband-1 packets). But it would be nice to detect and report the error, since it's likely to cause other confusion (we think the other side flushed, but they do not). - we try to detect packets missing their designator by checking for "if (len < 1)". But this will never trigger for "len == 0"; we've already detected that and left the function before then. It _could_ detect a negative "len" parameter. But in that case, the error message is wrong. The issue is not "no sideband" but rather "eof while reading the packet". However, this can't actually be triggered in practice, because neither of the two callers uses pkt_read's GENTLE_ON_EOF flag. Which means they'd die with "the remote end hung up unexpectedly" before we even get here. So this truly is dead code. We can improve these cases by passing in a pkt-line status to the demultiplexer, and by having recv_sideband() use GENTLE_ON_EOF. This gives us two improvements: - we can now reliably detect flush packets, and will report a normal packet missing its sideband designator as an error - we'll report an eof with a more detailed "protocol error: eof while reading sideband packet", rather than the generic "the remote end hung up unexpectedly" - when we see an eof, we'll flush the sideband scratch buffer, which may provide some hints from the remote about why they hung up (though note we already flush on newlines, so it's likely that most such messages already made it through) In some sense this patch goes against fbd76cd450 (sideband: reverse its dependency on pkt-line, 2019-01-16), which caused the sideband code not to depend on the pkt-line code. But that commit was really just trying to deal with the circular header dependency. The two modules are conceptually interlinked, and it was just trying to keep things compiling. And indeed, there's a sticking point in this patch: because pkt-line.h includes sideband.h, we can't add the reverse include we need for the sideband code to have an "enum packet_read_status" parameter. Nor can we forward declare it, because you can't forward declare an enum in C. However, C does guarantee that enums fit in an int, so we can just use that type. One alternative would be for the callers to check themselves that they got something sane from the pkt-line code. But besides duplicating logic, this gets quite tricky. Any error condition requires flushing the sideband #2 scratch buffer, which only demultiplex_sideband() knows how to do. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2 years ago
#include "pkt-line.h"
sideband: highlight keywords in remote sideband output The colorization is controlled with the config setting "color.remote". Supported keywords are "error", "warning", "hint" and "success". They are highlighted if they appear at the start of the line, which is common in error messages, eg. ERROR: commit is missing Change-Id The Git push process itself prints lots of non-actionable messages (eg. bandwidth statistics, object counters for different phases of the process). This obscures actionable error messages that servers may send back. Highlighting keywords in the sideband draws more attention to those messages. The background for this change is that Gerrit does server-side processing to create or update code reviews, and actionable error messages (eg. missing Change-Id) must be communicated back to the user during the push. User research has shown that new users have trouble seeing these messages. The highlighting is done on the client rather than server side, so servers don't have to grow capabilities to understand terminal escape codes and terminal state. It also consistent with the current state where Git is control of the local display (eg. prefixing messages with "remote: "). The highlighting can be configured using color.remote.<KEYWORD> configuration settings. Since the keys are matched case insensitively, we match the keywords case insensitively too. Finally, this solution is backwards compatible: many servers already prefix their messages with "error", and they will benefit from this change without requiring a server update. By contrast, a server-side solution would likely require plumbing the TERM variable through the git protocol, so it would require changes to both server and client. Helped-by: Duy Nguyen <pclouds@gmail.com> Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
4 years ago
struct keyword_entry {
/*
* We use keyword as config key so it should be a single alphanumeric word.
*/
const char *keyword;
char color[COLOR_MAXLEN];
};
static struct keyword_entry keywords[] = {
{ "hint", GIT_COLOR_YELLOW },
{ "warning", GIT_COLOR_BOLD_YELLOW },
{ "success", GIT_COLOR_BOLD_GREEN },
{ "error", GIT_COLOR_BOLD_RED },
};
/* Returns a color setting (GIT_COLOR_NEVER, etc). */
static int use_sideband_colors(void)
{
static int use_sideband_colors_cached = -1;
const char *key = "color.remote";
struct strbuf sb = STRBUF_INIT;
char *value;
int i;
if (use_sideband_colors_cached >= 0)
return use_sideband_colors_cached;
if (!git_config_get_string(key, &value)) {
use_sideband_colors_cached = git_config_colorbool(key, value);
} else if (!git_config_get_string("color.ui", &value)) {
use_sideband_colors_cached = git_config_colorbool("color.ui", value);
} else {
use_sideband_colors_cached = GIT_COLOR_AUTO;
}
for (i = 0; i < ARRAY_SIZE(keywords); i++) {
strbuf_reset(&sb);
strbuf_addf(&sb, "%s.%s", key, keywords[i].keyword);
if (git_config_get_string(sb.buf, &value))
continue;
if (color_parse(value, keywords[i].color))
continue;
}
strbuf_release(&sb);
return use_sideband_colors_cached;
}
void list_config_color_sideband_slots(struct string_list *list, const char *prefix)
{
int i;
for (i = 0; i < ARRAY_SIZE(keywords); i++)
list_config_item(list, prefix, keywords[i].keyword);
}
/*
* Optionally highlight one keyword in remote output if it appears at the start
* of the line. This should be called for a single line only, which is
* passed as the first N characters of the SRC array.
*
* NEEDSWORK: use "size_t n" instead for clarity.
sideband: highlight keywords in remote sideband output The colorization is controlled with the config setting "color.remote". Supported keywords are "error", "warning", "hint" and "success". They are highlighted if they appear at the start of the line, which is common in error messages, eg. ERROR: commit is missing Change-Id The Git push process itself prints lots of non-actionable messages (eg. bandwidth statistics, object counters for different phases of the process). This obscures actionable error messages that servers may send back. Highlighting keywords in the sideband draws more attention to those messages. The background for this change is that Gerrit does server-side processing to create or update code reviews, and actionable error messages (eg. missing Change-Id) must be communicated back to the user during the push. User research has shown that new users have trouble seeing these messages. The highlighting is done on the client rather than server side, so servers don't have to grow capabilities to understand terminal escape codes and terminal state. It also consistent with the current state where Git is control of the local display (eg. prefixing messages with "remote: "). The highlighting can be configured using color.remote.<KEYWORD> configuration settings. Since the keys are matched case insensitively, we match the keywords case insensitively too. Finally, this solution is backwards compatible: many servers already prefix their messages with "error", and they will benefit from this change without requiring a server update. By contrast, a server-side solution would likely require plumbing the TERM variable through the git protocol, so it would require changes to both server and client. Helped-by: Duy Nguyen <pclouds@gmail.com> Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
4 years ago
*/
static void maybe_colorize_sideband(struct strbuf *dest, const char *src, int n)
{
int i;
if (!want_color_stderr(use_sideband_colors())) {
strbuf_add(dest, src, n);
return;
}
while (0 < n && isspace(*src)) {
sideband: highlight keywords in remote sideband output The colorization is controlled with the config setting "color.remote". Supported keywords are "error", "warning", "hint" and "success". They are highlighted if they appear at the start of the line, which is common in error messages, eg. ERROR: commit is missing Change-Id The Git push process itself prints lots of non-actionable messages (eg. bandwidth statistics, object counters for different phases of the process). This obscures actionable error messages that servers may send back. Highlighting keywords in the sideband draws more attention to those messages. The background for this change is that Gerrit does server-side processing to create or update code reviews, and actionable error messages (eg. missing Change-Id) must be communicated back to the user during the push. User research has shown that new users have trouble seeing these messages. The highlighting is done on the client rather than server side, so servers don't have to grow capabilities to understand terminal escape codes and terminal state. It also consistent with the current state where Git is control of the local display (eg. prefixing messages with "remote: "). The highlighting can be configured using color.remote.<KEYWORD> configuration settings. Since the keys are matched case insensitively, we match the keywords case insensitively too. Finally, this solution is backwards compatible: many servers already prefix their messages with "error", and they will benefit from this change without requiring a server update. By contrast, a server-side solution would likely require plumbing the TERM variable through the git protocol, so it would require changes to both server and client. Helped-by: Duy Nguyen <pclouds@gmail.com> Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
4 years ago
strbuf_addch(dest, *src);
src++;
n--;
}
for (i = 0; i < ARRAY_SIZE(keywords); i++) {
struct keyword_entry *p = keywords + i;
int len = strlen(p->keyword);
if (n < len)
continue;
sideband: highlight keywords in remote sideband output The colorization is controlled with the config setting "color.remote". Supported keywords are "error", "warning", "hint" and "success". They are highlighted if they appear at the start of the line, which is common in error messages, eg. ERROR: commit is missing Change-Id The Git push process itself prints lots of non-actionable messages (eg. bandwidth statistics, object counters for different phases of the process). This obscures actionable error messages that servers may send back. Highlighting keywords in the sideband draws more attention to those messages. The background for this change is that Gerrit does server-side processing to create or update code reviews, and actionable error messages (eg. missing Change-Id) must be communicated back to the user during the push. User research has shown that new users have trouble seeing these messages. The highlighting is done on the client rather than server side, so servers don't have to grow capabilities to understand terminal escape codes and terminal state. It also consistent with the current state where Git is control of the local display (eg. prefixing messages with "remote: "). The highlighting can be configured using color.remote.<KEYWORD> configuration settings. Since the keys are matched case insensitively, we match the keywords case insensitively too. Finally, this solution is backwards compatible: many servers already prefix their messages with "error", and they will benefit from this change without requiring a server update. By contrast, a server-side solution would likely require plumbing the TERM variable through the git protocol, so it would require changes to both server and client. Helped-by: Duy Nguyen <pclouds@gmail.com> Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
4 years ago
/*
* Match case insensitively, so we colorize output from existing
* servers regardless of the case that they use for their
* messages. We only highlight the word precisely, so
* "successful" stays uncolored.
*/
if (!strncasecmp(p->keyword, src, len) &&
(len == n || !isalnum(src[len]))) {
sideband: highlight keywords in remote sideband output The colorization is controlled with the config setting "color.remote". Supported keywords are "error", "warning", "hint" and "success". They are highlighted if they appear at the start of the line, which is common in error messages, eg. ERROR: commit is missing Change-Id The Git push process itself prints lots of non-actionable messages (eg. bandwidth statistics, object counters for different phases of the process). This obscures actionable error messages that servers may send back. Highlighting keywords in the sideband draws more attention to those messages. The background for this change is that Gerrit does server-side processing to create or update code reviews, and actionable error messages (eg. missing Change-Id) must be communicated back to the user during the push. User research has shown that new users have trouble seeing these messages. The highlighting is done on the client rather than server side, so servers don't have to grow capabilities to understand terminal escape codes and terminal state. It also consistent with the current state where Git is control of the local display (eg. prefixing messages with "remote: "). The highlighting can be configured using color.remote.<KEYWORD> configuration settings. Since the keys are matched case insensitively, we match the keywords case insensitively too. Finally, this solution is backwards compatible: many servers already prefix their messages with "error", and they will benefit from this change without requiring a server update. By contrast, a server-side solution would likely require plumbing the TERM variable through the git protocol, so it would require changes to both server and client. Helped-by: Duy Nguyen <pclouds@gmail.com> Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
4 years ago
strbuf_addstr(dest, p->color);
strbuf_add(dest, src, len);
strbuf_addstr(dest, GIT_COLOR_RESET);
n -= len;
src += len;
break;
}
}
strbuf_add(dest, src, n);
}
#define DISPLAY_PREFIX "remote: "
#define ANSI_SUFFIX "\033[K"
#define DUMB_SUFFIX " "
sideband: diagnose more sideband anomalies In demultiplex_sideband(), there are two oddities when we check an incoming packet: - if it has zero length, then we assume it's a flush packet. This means we fail to notice the difference between a real flush and a true zero-length packet that's missing its sideband designator. It's not a huge problem in practice because we'd never send a zero-length data packet (even our keepalives are otherwise-empty sideband-1 packets). But it would be nice to detect and report the error, since it's likely to cause other confusion (we think the other side flushed, but they do not). - we try to detect packets missing their designator by checking for "if (len < 1)". But this will never trigger for "len == 0"; we've already detected that and left the function before then. It _could_ detect a negative "len" parameter. But in that case, the error message is wrong. The issue is not "no sideband" but rather "eof while reading the packet". However, this can't actually be triggered in practice, because neither of the two callers uses pkt_read's GENTLE_ON_EOF flag. Which means they'd die with "the remote end hung up unexpectedly" before we even get here. So this truly is dead code. We can improve these cases by passing in a pkt-line status to the demultiplexer, and by having recv_sideband() use GENTLE_ON_EOF. This gives us two improvements: - we can now reliably detect flush packets, and will report a normal packet missing its sideband designator as an error - we'll report an eof with a more detailed "protocol error: eof while reading sideband packet", rather than the generic "the remote end hung up unexpectedly" - when we see an eof, we'll flush the sideband scratch buffer, which may provide some hints from the remote about why they hung up (though note we already flush on newlines, so it's likely that most such messages already made it through) In some sense this patch goes against fbd76cd450 (sideband: reverse its dependency on pkt-line, 2019-01-16), which caused the sideband code not to depend on the pkt-line code. But that commit was really just trying to deal with the circular header dependency. The two modules are conceptually interlinked, and it was just trying to keep things compiling. And indeed, there's a sticking point in this patch: because pkt-line.h includes sideband.h, we can't add the reverse include we need for the sideband code to have an "enum packet_read_status" parameter. Nor can we forward declare it, because you can't forward declare an enum in C. However, C does guarantee that enums fit in an int, so we can just use that type. One alternative would be for the callers to check themselves that they got something sane from the pkt-line code. But besides duplicating logic, this gets quite tricky. Any error condition requires flushing the sideband #2 scratch buffer, which only demultiplex_sideband() knows how to do. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2 years ago
int demultiplex_sideband(const char *me, int status,
char *buf, int len,
int die_on_error,
struct strbuf *scratch,
enum sideband_type *sideband_type)
{
static const char *suffix;
const char *b, *brk;
int band;
if (!suffix) {
if (isatty(2) && !is_terminal_dumb())
suffix = ANSI_SUFFIX;
else
suffix = DUMB_SUFFIX;
}
sideband: diagnose more sideband anomalies In demultiplex_sideband(), there are two oddities when we check an incoming packet: - if it has zero length, then we assume it's a flush packet. This means we fail to notice the difference between a real flush and a true zero-length packet that's missing its sideband designator. It's not a huge problem in practice because we'd never send a zero-length data packet (even our keepalives are otherwise-empty sideband-1 packets). But it would be nice to detect and report the error, since it's likely to cause other confusion (we think the other side flushed, but they do not). - we try to detect packets missing their designator by checking for "if (len < 1)". But this will never trigger for "len == 0"; we've already detected that and left the function before then. It _could_ detect a negative "len" parameter. But in that case, the error message is wrong. The issue is not "no sideband" but rather "eof while reading the packet". However, this can't actually be triggered in practice, because neither of the two callers uses pkt_read's GENTLE_ON_EOF flag. Which means they'd die with "the remote end hung up unexpectedly" before we even get here. So this truly is dead code. We can improve these cases by passing in a pkt-line status to the demultiplexer, and by having recv_sideband() use GENTLE_ON_EOF. This gives us two improvements: - we can now reliably detect flush packets, and will report a normal packet missing its sideband designator as an error - we'll report an eof with a more detailed "protocol error: eof while reading sideband packet", rather than the generic "the remote end hung up unexpectedly" - when we see an eof, we'll flush the sideband scratch buffer, which may provide some hints from the remote about why they hung up (though note we already flush on newlines, so it's likely that most such messages already made it through) In some sense this patch goes against fbd76cd450 (sideband: reverse its dependency on pkt-line, 2019-01-16), which caused the sideband code not to depend on the pkt-line code. But that commit was really just trying to deal with the circular header dependency. The two modules are conceptually interlinked, and it was just trying to keep things compiling. And indeed, there's a sticking point in this patch: because pkt-line.h includes sideband.h, we can't add the reverse include we need for the sideband code to have an "enum packet_read_status" parameter. Nor can we forward declare it, because you can't forward declare an enum in C. However, C does guarantee that enums fit in an int, so we can just use that type. One alternative would be for the callers to check themselves that they got something sane from the pkt-line code. But besides duplicating logic, this gets quite tricky. Any error condition requires flushing the sideband #2 scratch buffer, which only demultiplex_sideband() knows how to do. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2 years ago
if (status == PACKET_READ_EOF) {
strbuf_addf(scratch,
sideband: diagnose more sideband anomalies In demultiplex_sideband(), there are two oddities when we check an incoming packet: - if it has zero length, then we assume it's a flush packet. This means we fail to notice the difference between a real flush and a true zero-length packet that's missing its sideband designator. It's not a huge problem in practice because we'd never send a zero-length data packet (even our keepalives are otherwise-empty sideband-1 packets). But it would be nice to detect and report the error, since it's likely to cause other confusion (we think the other side flushed, but they do not). - we try to detect packets missing their designator by checking for "if (len < 1)". But this will never trigger for "len == 0"; we've already detected that and left the function before then. It _could_ detect a negative "len" parameter. But in that case, the error message is wrong. The issue is not "no sideband" but rather "eof while reading the packet". However, this can't actually be triggered in practice, because neither of the two callers uses pkt_read's GENTLE_ON_EOF flag. Which means they'd die with "the remote end hung up unexpectedly" before we even get here. So this truly is dead code. We can improve these cases by passing in a pkt-line status to the demultiplexer, and by having recv_sideband() use GENTLE_ON_EOF. This gives us two improvements: - we can now reliably detect flush packets, and will report a normal packet missing its sideband designator as an error - we'll report an eof with a more detailed "protocol error: eof while reading sideband packet", rather than the generic "the remote end hung up unexpectedly" - when we see an eof, we'll flush the sideband scratch buffer, which may provide some hints from the remote about why they hung up (though note we already flush on newlines, so it's likely that most such messages already made it through) In some sense this patch goes against fbd76cd450 (sideband: reverse its dependency on pkt-line, 2019-01-16), which caused the sideband code not to depend on the pkt-line code. But that commit was really just trying to deal with the circular header dependency. The two modules are conceptually interlinked, and it was just trying to keep things compiling. And indeed, there's a sticking point in this patch: because pkt-line.h includes sideband.h, we can't add the reverse include we need for the sideband code to have an "enum packet_read_status" parameter. Nor can we forward declare it, because you can't forward declare an enum in C. However, C does guarantee that enums fit in an int, so we can just use that type. One alternative would be for the callers to check themselves that they got something sane from the pkt-line code. But besides duplicating logic, this gets quite tricky. Any error condition requires flushing the sideband #2 scratch buffer, which only demultiplex_sideband() knows how to do. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2 years ago
"%s%s: unexpected disconnect while reading sideband packet",
scratch->len ? "\n" : "", me);
*sideband_type = SIDEBAND_PROTOCOL_ERROR;
goto cleanup;
}
sideband: diagnose more sideband anomalies In demultiplex_sideband(), there are two oddities when we check an incoming packet: - if it has zero length, then we assume it's a flush packet. This means we fail to notice the difference between a real flush and a true zero-length packet that's missing its sideband designator. It's not a huge problem in practice because we'd never send a zero-length data packet (even our keepalives are otherwise-empty sideband-1 packets). But it would be nice to detect and report the error, since it's likely to cause other confusion (we think the other side flushed, but they do not). - we try to detect packets missing their designator by checking for "if (len < 1)". But this will never trigger for "len == 0"; we've already detected that and left the function before then. It _could_ detect a negative "len" parameter. But in that case, the error message is wrong. The issue is not "no sideband" but rather "eof while reading the packet". However, this can't actually be triggered in practice, because neither of the two callers uses pkt_read's GENTLE_ON_EOF flag. Which means they'd die with "the remote end hung up unexpectedly" before we even get here. So this truly is dead code. We can improve these cases by passing in a pkt-line status to the demultiplexer, and by having recv_sideband() use GENTLE_ON_EOF. This gives us two improvements: - we can now reliably detect flush packets, and will report a normal packet missing its sideband designator as an error - we'll report an eof with a more detailed "protocol error: eof while reading sideband packet", rather than the generic "the remote end hung up unexpectedly" - when we see an eof, we'll flush the sideband scratch buffer, which may provide some hints from the remote about why they hung up (though note we already flush on newlines, so it's likely that most such messages already made it through) In some sense this patch goes against fbd76cd450 (sideband: reverse its dependency on pkt-line, 2019-01-16), which caused the sideband code not to depend on the pkt-line code. But that commit was really just trying to deal with the circular header dependency. The two modules are conceptually interlinked, and it was just trying to keep things compiling. And indeed, there's a sticking point in this patch: because pkt-line.h includes sideband.h, we can't add the reverse include we need for the sideband code to have an "enum packet_read_status" parameter. Nor can we forward declare it, because you can't forward declare an enum in C. However, C does guarantee that enums fit in an int, so we can just use that type. One alternative would be for the callers to check themselves that they got something sane from the pkt-line code. But besides duplicating logic, this gets quite tricky. Any error condition requires flushing the sideband #2 scratch buffer, which only demultiplex_sideband() knows how to do. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2 years ago
if (len < 0)
BUG("negative length on non-eof packet read");
if (len == 0) {
if (status == PACKET_READ_NORMAL) {
strbuf_addf(scratch,
"%s%s: protocol error: missing sideband designator",
scratch->len ? "\n" : "", me);
*sideband_type = SIDEBAND_PROTOCOL_ERROR;
} else {
/* covers flush, delim, etc */
*sideband_type = SIDEBAND_FLUSH;
}
goto cleanup;
}
band = buf[0] & 0xff;
buf[len] = '\0';
len--;
switch (band) {
case 3:
if (die_on_error)
die(_("remote error: %s"), buf + 1);
strbuf_addf(scratch, "%s%s", scratch->len ? "\n" : "",
DISPLAY_PREFIX);
maybe_colorize_sideband(scratch, buf + 1, len);
*sideband_type = SIDEBAND_REMOTE_ERROR;
break;
case 2:
b = buf + 1;
/*
* Append a suffix to each nonempty line to clear the
* end of the screen line.
*
* The output is accumulated in a buffer and
* each line is printed to stderr using
* write(2) to ensure inter-process atomicity.
*/
while ((brk = strpbrk(b, "\n\r"))) {
int linelen = brk - b;
/*
* For message accross packet boundary, there would have
* a nonempty "scratch" buffer from last call of this
* function, and there may have a leading CR/LF in "buf".
* For this case we should add a clear-to-eol suffix to
* clean leftover letters we previously have written on
* the same line.
*/
if (scratch->len && !linelen)
strbuf_addstr(scratch, suffix);
if (!scratch->len)
strbuf_addstr(scratch, DISPLAY_PREFIX);
/*
* A use case that we should not add clear-to-eol suffix
* to empty lines:
*
* For progress reporting we may receive a bunch of
* percentage updates followed by '\r' to remain on the
* same line, and at the end receive a single '\n' to
* move to the next line. We should preserve the final
* status report line by not appending clear-to-eol
* suffix to this single line break.
*/
if (linelen > 0) {
maybe_colorize_sideband(scratch, b, linelen);
strbuf_addstr(scratch, suffix);
sideband: highlight keywords in remote sideband output The colorization is controlled with the config setting "color.remote". Supported keywords are "error", "warning", "hint" and "success". They are highlighted if they appear at the start of the line, which is common in error messages, eg. ERROR: commit is missing Change-Id The Git push process itself prints lots of non-actionable messages (eg. bandwidth statistics, object counters for different phases of the process). This obscures actionable error messages that servers may send back. Highlighting keywords in the sideband draws more attention to those messages. The background for this change is that Gerrit does server-side processing to create or update code reviews, and actionable error messages (eg. missing Change-Id) must be communicated back to the user during the push. User research has shown that new users have trouble seeing these messages. The highlighting is done on the client rather than server side, so servers don't have to grow capabilities to understand terminal escape codes and terminal state. It also consistent with the current state where Git is control of the local display (eg. prefixing messages with "remote: "). The highlighting can be configured using color.remote.<KEYWORD> configuration settings. Since the keys are matched case insensitively, we match the keywords case insensitively too. Finally, this solution is backwards compatible: many servers already prefix their messages with "error", and they will benefit from this change without requiring a server update. By contrast, a server-side solution would likely require plumbing the TERM variable through the git protocol, so it would require changes to both server and client. Helped-by: Duy Nguyen <pclouds@gmail.com> Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
4 years ago
}
strbuf_addch(scratch, *brk);
xwrite(2, scratch->buf, scratch->len);
strbuf_reset(scratch);
b = brk + 1;
}
if (*b) {
strbuf_addstr(scratch, scratch->len ?
"" : DISPLAY_PREFIX);
maybe_colorize_sideband(scratch, b, strlen(b));
}
return 0;
case 1:
*sideband_type = SIDEBAND_PRIMARY;
sideband: avoid reporting incomplete sideband messages In 2b695ecd74d (t5500: count objects through stderr, not trace, 2020-05-06) we tried to ensure that the "Total 3" message could be grepped in Git's output, even if it sometimes got chopped up into multiple lines in the trace machinery. However, the first instance where this mattered now goes through the sideband machinery, where it is _still_ possible for messages to get chopped up: it *is* possible for the standard error stream to be sent byte-for-byte and hence it can be easily interrupted. Meaning: it is possible for the single line that we're looking for to be chopped up into multiple sideband packets, with a primary packet being delivered between them. This seems to happen occasionally in the `vs-test` part of our CI builds, i.e. with binaries built using Visual C, but not when building with GCC or clang; The symptom is that t5500.43 fails to find a line matching `remote: Total 3` in the `log` file, which ends in something along these lines: remote: Tota remote: l 3 (delta 0), reused 0 (delta 0), pack-reused 0 This should not happen, though: we have code in `demultiplex_sideband()` _specifically_ to stitch back together lines that were delivered in separate sideband packets. However, this stitching was broken in a subtle way in fbd76cd450 (sideband: reverse its dependency on pkt-line, 2019-01-16): before that change, incomplete sideband lines would not be flushed upon receiving a primary packet, but after that patch, they would be. The subtleness of this bug comes from the fact that it is easy to get confused by the ambiguous meaning of the `break` keyword: after writing the primary packet contents, the `break;` in the original version of `recv_sideband()` does _not_ break out of the `while` loop, but instead only ends the `switch` case: while (!retval) { [...] switch (band) { [...] case 1: /* Write the contents of the primary packet */ write_or_die(out, buf + 1, len); /* Here, we do *not* break out of the loop, `retval` is unchanged */ break; [...] } if (outbuf.len) { /* Write any remaining sideband messages lacking a trailing LF */ strbuf_addch(&outbuf, '\n'); xwrite(2, outbuf.buf, outbuf.len); } In contrast, after fbd76cd450 (sideband: reverse its dependency on pkt-line, 2019-01-16), the body of the `while` loop was extracted into `demultiplex_sideband()`, crucially _including_ the logic to write incomplete sideband messages: switch (band) { [...] case 1: *sideband_type = SIDEBAND_PRIMARY; /* This does not break out of the loop: the loop is in the caller */ break; [...] } cleanup: [...] /* This logic is now no longer _outside_ the loop but _inside_ */ if (scratch->len) { strbuf_addch(scratch, '\n'); xwrite(2, scratch->buf, scratch->len); } The correct way to fix this is to return from `demultiplex_sideband()` early. The caller will then write out the contents of the primary packet and continue looping. The `scratch` buffer for incomplete sideband messages is owned by that caller, and will continue to accumulate the remainder(s) of those messages. The loop will only end once `demultiplex_sideband()` returned non-zero _and_ did not indicate a primary packet, which is the case only when we hit the `cleanup:` path, in which we take care of flushing any unfinished sideband messages and release the `scratch` buffer. To ensure that this does not get broken again, we introduce a pair of subcommands of the `pkt-line` test helper that specifically chop up the sideband message and squeeze a primary packet into the middle. Final note: The other test case touched by 2b695ecd74d (t5500: count objects through stderr, not trace, 2020-05-06) is not affected by this issue because the sideband machinery is not involved there. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2 years ago
return 1;
default:
strbuf_addf(scratch, "%s%s: protocol error: bad band #%d",
scratch->len ? "\n" : "", me, band);
*sideband_type = SIDEBAND_PROTOCOL_ERROR;
break;
}
cleanup:
if (die_on_error && *sideband_type == SIDEBAND_PROTOCOL_ERROR)
die("%s", scratch->buf);
if (scratch->len) {
strbuf_addch(scratch, '\n');
xwrite(2, scratch->buf, scratch->len);
}
strbuf_release(scratch);
return 1;
}
/*
* fd is connected to the remote side; send the sideband data
* over multiplexed packet stream.
*/
void send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max)
{
const char *p = data;
while (sz) {
unsigned n;
char hdr[5];
n = sz;
if (packet_max - 5 < n)
n = packet_max - 5;
if (0 <= band) {
xsnprintf(hdr, sizeof(hdr), "%04x", n + 5);
hdr[4] = band;
write_or_die(fd, hdr, 5);
} else {
xsnprintf(hdr, sizeof(hdr), "%04x", n + 4);
write_or_die(fd, hdr, 4);
}
write_or_die(fd, p, n);
p += n;
sz -= n;
}
}