Hydration round-trips every fetched value through std::wstring (lossy + slow reads) #17

Closed
#31
Closed
Hydration round-trips every fetched value through std::wstring (lossy + slow reads)#17
#31
Labels
bugSomething isn't workingenhancementNew feature or requestperformance

Description

@jkalias
jkalias
opened on Jun 15, 2026

Problem

Database::Fetch builds a FetchQueryResults whose row_values is a std::vector<std::vector<std::wstring>> (include/fetch_query_results.h). FetchRecordsQuery::GetResults stringifies every column into a wstring via GetColumnValue, and FetchRecordsQuery::Hydrate then parses each string back into the typed member. This text round-trip on the read path is both a performance cost and the root cause of two concrete data-corruption bugs.

Concrete defects caused by the text round-trip

1. 64-bit integers truncated to 32 bits (consolidated from #15)
GetColumnValue reads SQLITE_INTEGER with the 32-bit sqlite3_column_int (return std::to_wstring(sqlite3_column_int(stmt_, col));), and FetchMaxIdQuery::GetMaxId does the same. Any stored int64_t above INT32_MAX — including AUTOINCREMENT ids once they grow large — is silently truncated/wrapped on read, breaking subsequent Fetch(id) / Update / Delete. Fix: use sqlite3_column_int64.

2. REAL values lose precision (consolidated from #16)
GetColumnValue formats SQLITE_FLOAT via std::to_wstring(double), which uses %f with a fixed 6 decimal places, so e.g. 0.123456789 round-trips back as 0.123457 and large/scientific magnitudes are mangled. Writes are fine (sqlite3_bind_double stores the true value); the loss is only on the read path. Fix: read sqlite3_column_double directly, or format with full round-trip precision (%.17g).

Performance / memory

  • Every value incurs an allocation + parse on top of the SQLite copy; significant for wide rows / large result sets.
  • The entire result set is materialized as strings before hydration (no streaming), so large queries hold the whole set twice (string + typed form).

Suggested direction

Hydrate directly from the prepared statement using the typed column accessors (sqlite3_column_int64, sqlite3_column_double, sqlite3_column_text/_bytes) into the destination members, skipping the intermediate wstring. This removes the per-value allocation/parse, fixes both data-corruption bugs above at the source, and opens the door to row-by-row streaming.

Acceptance criteria

  • Integer columns round-trip values greater than INT32_MAX exactly (regression test).
  • Double columns round-trip high-precision values exactly (regression test).
  • Hydration reads typed columns directly rather than via std::wstring.

Related (tracked separately)

Consolidates #15 (int truncation) and #16 (REAL precision), which were symptoms of this single root cause and are closed as duplicates of this issue.

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      , 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
       blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

      Skip to content
      Hydration round-trips every fetched value through std::wstring (lossy + slow reads) #17
      Closed
      #31
      Closed
      Hydration round-trips every fetched value through std::wstring (lossy + slow reads)#17
      #31
      Labels
      bugSomething isn't workingenhancementNew feature or requestperformance
      Description
      @jkalias
      jkalias
      opened on Jun 15, 2026
      Problem
      Database::Fetch builds a FetchQueryResults whose row_values is a std::vector<std::vector<std::wstring>> (include/fetch_query_results.h). FetchRecordsQuery::GetResults stringifies every column into a wstring via GetColumnValue, and FetchRecordsQuery::Hydrate then parses each string back into the typed member. This text round-trip on the read path is both a performance cost and the root cause of two concrete data-corruption bugs.
      Concrete defects caused by the text round-trip
      1. 64-bit integers truncated to 32 bits (consolidated from #15)
      GetColumnValue reads SQLITE_INTEGER with the 32-bit sqlite3_column_int (return std::to_wstring(sqlite3_column_int(stmt_, col));), and FetchMaxIdQuery::GetMaxId does the same. Any stored int64_t above INT32_MAX — including AUTOINCREMENT ids once they grow large — is silently truncated/wrapped on read, breaking subsequent Fetch(id) / Update / Delete. Fix: use sqlite3_column_int64.
      2. REAL values lose precision (consolidated from #16)
      GetColumnValue formats SQLITE_FLOAT via std::to_wstring(double), which uses %f with a fixed 6 decimal places, so e.g. 0.123456789 round-trips back as 0.123457 and large/scientific magnitudes are mangled. Writes are fine (sqlite3_bind_double stores the true value); the loss is only on the read path. Fix: read sqlite3_column_double directly, or format with full round-trip precision (%.17g).
      Performance / memory
      • Every value incurs an allocation + parse on top of the SQLite copy; significant for wide rows / large result sets.
      • The entire result set is materialized as strings before hydration (no streaming), so large queries hold the whole set twice (string + typed form).
      Suggested direction
      Hydrate directly from the prepared statement using the typed column accessors (sqlite3_column_int64, sqlite3_column_double, sqlite3_column_text/_bytes) into the destination members, skipping the intermediate wstring. This removes the per-value allocation/parse, fixes both data-corruption bugs above at the source, and opens the door to row-by-row streaming.
      Acceptance criteria
      • Integer columns round-trip values greater than INT32_MAX exactly (regression test).
      • Double columns round-trip high-precision values exactly (regression test).
      • Hydration reads typed columns directly rather than via std::wstring.
      Related (tracked separately)
      Consolidates #15 (int truncation) and #16 (REAL precision), which were symptoms of this single root cause and are closed as duplicates of this issue.
      Metadata
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      No one assigned
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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

          Skip to content
          Hydration round-trips every fetched value through std::wstring (lossy + slow reads) #17
          Closed
          #31
          Closed
          Hydration round-trips every fetched value through std::wstring (lossy + slow reads)#17
          #31
          Labels
          bugSomething isn't workingenhancementNew feature or requestperformance
          Description
          @jkalias
          jkalias
          opened on Jun 15, 2026
          Problem
          Database::Fetch builds a FetchQueryResults whose row_values is a std::vector<std::vector<std::wstring>> (include/fetch_query_results.h). FetchRecordsQuery::GetResults stringifies every column into a wstring via GetColumnValue, and FetchRecordsQuery::Hydrate then parses each string back into the typed member. This text round-trip on the read path is both a performance cost and the root cause of two concrete data-corruption bugs.
          Concrete defects caused by the text round-trip
          1. 64-bit integers truncated to 32 bits (consolidated from #15)
          GetColumnValue reads SQLITE_INTEGER with the 32-bit sqlite3_column_int (return std::to_wstring(sqlite3_column_int(stmt_, col));), and FetchMaxIdQuery::GetMaxId does the same. Any stored int64_t above INT32_MAX — including AUTOINCREMENT ids once they grow large — is silently truncated/wrapped on read, breaking subsequent Fetch(id) / Update / Delete. Fix: use sqlite3_column_int64.
          2. REAL values lose precision (consolidated from #16)
          GetColumnValue formats SQLITE_FLOAT via std::to_wstring(double), which uses %f with a fixed 6 decimal places, so e.g. 0.123456789 round-trips back as 0.123457 and large/scientific magnitudes are mangled. Writes are fine (sqlite3_bind_double stores the true value); the loss is only on the read path. Fix: read sqlite3_column_double directly, or format with full round-trip precision (%.17g).
          Performance / memory
          • Every value incurs an allocation + parse on top of the SQLite copy; significant for wide rows / large result sets.
          • The entire result set is materialized as strings before hydration (no streaming), so large queries hold the whole set twice (string + typed form).
          Suggested direction
          Hydrate directly from the prepared statement using the typed column accessors (sqlite3_column_int64, sqlite3_column_double, sqlite3_column_text/_bytes) into the destination members, skipping the intermediate wstring. This removes the per-value allocation/parse, fixes both data-corruption bugs above at the source, and opens the door to row-by-row streaming.
          Acceptance criteria
          • Integer columns round-trip values greater than INT32_MAX exactly (regression test).
          • Double columns round-trip high-precision values exactly (regression test).
          • Hydration reads typed columns directly rather than via std::wstring.
          Related (tracked separately)
          Consolidates #15 (int truncation) and #16 (REAL precision), which were symptoms of this single root cause and are closed as duplicates of this issue.
          Metadata
          Metadata
          Assignees
          No one assigned
            Labels
            bugSomething isn't workingenhancementNew feature or requestperformance
            Projects
            No projects
              Milestone
              No milestone
              Relationships
              None yet
              Development
              No branches or pull requests
              Issue actions
              
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

              Skip to content
              Hydration round-trips every fetched value through std::wstring (lossy + slow reads) #17
              Closed
              #31
              Closed
              Hydration round-trips every fetched value through std::wstring (lossy + slow reads)#17
              #31
              Labels
              bugSomething isn't workingenhancementNew feature or requestperformance
              Description
              @jkalias
              jkalias
              opened on Jun 15, 2026
              Problem
              Database::Fetch builds a FetchQueryResults whose row_values is a std::vector<std::vector<std::wstring>> (include/fetch_query_results.h). FetchRecordsQuery::GetResults stringifies every column into a wstring via GetColumnValue, and FetchRecordsQuery::Hydrate then parses each string back into the typed member. This text round-trip on the read path is both a performance cost and the root cause of two concrete data-corruption bugs.
              Concrete defects caused by the text round-trip
              1. 64-bit integers truncated to 32 bits (consolidated from #15)
              GetColumnValue reads SQLITE_INTEGER with the 32-bit sqlite3_column_int (return std::to_wstring(sqlite3_column_int(stmt_, col));), and FetchMaxIdQuery::GetMaxId does the same. Any stored int64_t above INT32_MAX — including AUTOINCREMENT ids once they grow large — is silently truncated/wrapped on read, breaking subsequent Fetch(id) / Update / Delete. Fix: use sqlite3_column_int64.
              2. REAL values lose precision (consolidated from #16)
              GetColumnValue formats SQLITE_FLOAT via std::to_wstring(double), which uses %f with a fixed 6 decimal places, so e.g. 0.123456789 round-trips back as 0.123457 and large/scientific magnitudes are mangled. Writes are fine (sqlite3_bind_double stores the true value); the loss is only on the read path. Fix: read sqlite3_column_double directly, or format with full round-trip precision (%.17g).
              Performance / memory
              • Every value incurs an allocation + parse on top of the SQLite copy; significant for wide rows / large result sets.
              • The entire result set is materialized as strings before hydration (no streaming), so large queries hold the whole set twice (string + typed form).
              Suggested direction
              Hydrate directly from the prepared statement using the typed column accessors (sqlite3_column_int64, sqlite3_column_double, sqlite3_column_text/_bytes) into the destination members, skipping the intermediate wstring. This removes the per-value allocation/parse, fixes both data-corruption bugs above at the source, and opens the door to row-by-row streaming.
              Acceptance criteria
              • Integer columns round-trip values greater than INT32_MAX exactly (regression test).
              • Double columns round-trip high-precision values exactly (regression test).
              • Hydration reads typed columns directly rather than via std::wstring.
              Related (tracked separately)
              Consolidates #15 (int truncation) and #16 (REAL precision), which were symptoms of this single root cause and are closed as duplicates of this issue.
              Metadata
              Metadata
              Assignees
              No one assigned
                Labels
                bugSomething isn't workingenhancementNew feature or requestperformance
                Projects
                No projects
                  Milestone
                  No milestone
                  Relationships
                  None yet
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                  No branches or pull requests
                  Issue actions
                  
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

                  Skip to content
                  Hydration round-trips every fetched value through std::wstring (lossy + slow reads) #17
                  Closed
                  #31
                  Closed
                  Hydration round-trips every fetched value through std::wstring (lossy + slow reads)#17
                  #31
                  Labels
                  bugSomething isn't workingenhancementNew feature or requestperformance
                  Description
                  @jkalias
                  jkalias
                  opened on Jun 15, 2026
                  Problem
                  Database::Fetch builds a FetchQueryResults whose row_values is a std::vector<std::vector<std::wstring>> (include/fetch_query_results.h). FetchRecordsQuery::GetResults stringifies every column into a wstring via GetColumnValue, and FetchRecordsQuery::Hydrate then parses each string back into the typed member. This text round-trip on the read path is both a performance cost and the root cause of two concrete data-corruption bugs.
                  Concrete defects caused by the text round-trip
                  1. 64-bit integers truncated to 32 bits (consolidated from #15)
                  GetColumnValue reads SQLITE_INTEGER with the 32-bit sqlite3_column_int (return std::to_wstring(sqlite3_column_int(stmt_, col));), and FetchMaxIdQuery::GetMaxId does the same. Any stored int64_t above INT32_MAX — including AUTOINCREMENT ids once they grow large — is silently truncated/wrapped on read, breaking subsequent Fetch(id) / Update / Delete. Fix: use sqlite3_column_int64.
                  2. REAL values lose precision (consolidated from #16)
                  GetColumnValue formats SQLITE_FLOAT via std::to_wstring(double), which uses %f with a fixed 6 decimal places, so e.g. 0.123456789 round-trips back as 0.123457 and large/scientific magnitudes are mangled. Writes are fine (sqlite3_bind_double stores the true value); the loss is only on the read path. Fix: read sqlite3_column_double directly, or format with full round-trip precision (%.17g).
                  Performance / memory
                  • Every value incurs an allocation + parse on top of the SQLite copy; significant for wide rows / large result sets.
                  • The entire result set is materialized as strings before hydration (no streaming), so large queries hold the whole set twice (string + typed form).
                  Suggested direction
                  Hydrate directly from the prepared statement using the typed column accessors (sqlite3_column_int64, sqlite3_column_double, sqlite3_column_text/_bytes) into the destination members, skipping the intermediate wstring. This removes the per-value allocation/parse, fixes both data-corruption bugs above at the source, and opens the door to row-by-row streaming.
                  Acceptance criteria
                  • Integer columns round-trip values greater than INT32_MAX exactly (regression test).
                  • Double columns round-trip high-precision values exactly (regression test).
                  • Hydration reads typed columns directly rather than via std::wstring.
                  Related (tracked separately)
                  Consolidates #15 (int truncation) and #16 (REAL precision), which were symptoms of this single root cause and are closed as duplicates of this issue.
                  Metadata
                  Metadata
                  Assignees
                  No one assigned
                    Labels
                    bugSomething isn't workingenhancementNew feature or requestperformance
                    Projects
                    No projects
                      Milestone
                      No milestone
                      Relationships
                      None yet
                      Development
                      No branches or pull requests
                      Issue actions
                      
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

                      Skip to content
                      Hydration round-trips every fetched value through std::wstring (lossy + slow reads) #17
                      Closed
                      #31
                      Closed
                      Hydration round-trips every fetched value through std::wstring (lossy + slow reads)#17
                      #31
                      Labels
                      bugSomething isn't workingenhancementNew feature or requestperformance
                      Description
                      @jkalias
                      jkalias
                      opened on Jun 15, 2026
                      Problem
                      Database::Fetch builds a FetchQueryResults whose row_values is a std::vector<std::vector<std::wstring>> (include/fetch_query_results.h). FetchRecordsQuery::GetResults stringifies every column into a wstring via GetColumnValue, and FetchRecordsQuery::Hydrate then parses each string back into the typed member. This text round-trip on the read path is both a performance cost and the root cause of two concrete data-corruption bugs.
                      Concrete defects caused by the text round-trip
                      1. 64-bit integers truncated to 32 bits (consolidated from #15)
                      GetColumnValue reads SQLITE_INTEGER with the 32-bit sqlite3_column_int (return std::to_wstring(sqlite3_column_int(stmt_, col));), and FetchMaxIdQuery::GetMaxId does the same. Any stored int64_t above INT32_MAX — including AUTOINCREMENT ids once they grow large — is silently truncated/wrapped on read, breaking subsequent Fetch(id) / Update / Delete. Fix: use sqlite3_column_int64.
                      2. REAL values lose precision (consolidated from #16)
                      GetColumnValue formats SQLITE_FLOAT via std::to_wstring(double), which uses %f with a fixed 6 decimal places, so e.g. 0.123456789 round-trips back as 0.123457 and large/scientific magnitudes are mangled. Writes are fine (sqlite3_bind_double stores the true value); the loss is only on the read path. Fix: read sqlite3_column_double directly, or format with full round-trip precision (%.17g).
                      Performance / memory
                      • Every value incurs an allocation + parse on top of the SQLite copy; significant for wide rows / large result sets.
                      • The entire result set is materialized as strings before hydration (no streaming), so large queries hold the whole set twice (string + typed form).
                      Suggested direction
                      Hydrate directly from the prepared statement using the typed column accessors (sqlite3_column_int64, sqlite3_column_double, sqlite3_column_text/_bytes) into the destination members, skipping the intermediate wstring. This removes the per-value allocation/parse, fixes both data-corruption bugs above at the source, and opens the door to row-by-row streaming.
                      Acceptance criteria
                      • Integer columns round-trip values greater than INT32_MAX exactly (regression test).
                      • Double columns round-trip high-precision values exactly (regression test).
                      • Hydration reads typed columns directly rather than via std::wstring.
                      Related (tracked separately)
                      Consolidates #15 (int truncation) and #16 (REAL precision), which were symptoms of this single root cause and are closed as duplicates of this issue.
                      Metadata
                      Metadata
                      Assignees
                      No one assigned
                        Labels
                        bugSomething isn't workingenhancementNew feature or requestperformance
                        Projects
                        No projects
                          Milestone
                          No milestone
                          Relationships
                          None yet
                          Development
                          No branches or pull requests
                          Issue actions
                          
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

                          Skip to content
                          Hydration round-trips every fetched value through std::wstring (lossy + slow reads) #17
                          Closed
                          #31
                          Closed
                          Hydration round-trips every fetched value through std::wstring (lossy + slow reads)#17
                          #31
                          Labels
                          bugSomething isn't workingenhancementNew feature or requestperformance
                          Description
                          @jkalias
                          jkalias
                          opened on Jun 15, 2026
                          Problem
                          Database::Fetch builds a FetchQueryResults whose row_values is a std::vector<std::vector<std::wstring>> (include/fetch_query_results.h). FetchRecordsQuery::GetResults stringifies every column into a wstring via GetColumnValue, and FetchRecordsQuery::Hydrate then parses each string back into the typed member. This text round-trip on the read path is both a performance cost and the root cause of two concrete data-corruption bugs.
                          Concrete defects caused by the text round-trip
                          1. 64-bit integers truncated to 32 bits (consolidated from #15)
                          GetColumnValue reads SQLITE_INTEGER with the 32-bit sqlite3_column_int (return std::to_wstring(sqlite3_column_int(stmt_, col));), and FetchMaxIdQuery::GetMaxId does the same. Any stored int64_t above INT32_MAX — including AUTOINCREMENT ids once they grow large — is silently truncated/wrapped on read, breaking subsequent Fetch(id) / Update / Delete. Fix: use sqlite3_column_int64.
                          2. REAL values lose precision (consolidated from #16)
                          GetColumnValue formats SQLITE_FLOAT via std::to_wstring(double), which uses %f with a fixed 6 decimal places, so e.g. 0.123456789 round-trips back as 0.123457 and large/scientific magnitudes are mangled. Writes are fine (sqlite3_bind_double stores the true value); the loss is only on the read path. Fix: read sqlite3_column_double directly, or format with full round-trip precision (%.17g).
                          Performance / memory
                          • Every value incurs an allocation + parse on top of the SQLite copy; significant for wide rows / large result sets.
                          • The entire result set is materialized as strings before hydration (no streaming), so large queries hold the whole set twice (string + typed form).
                          Suggested direction
                          Hydrate directly from the prepared statement using the typed column accessors (sqlite3_column_int64, sqlite3_column_double, sqlite3_column_text/_bytes) into the destination members, skipping the intermediate wstring. This removes the per-value allocation/parse, fixes both data-corruption bugs above at the source, and opens the door to row-by-row streaming.
                          Acceptance criteria
                          • Integer columns round-trip values greater than INT32_MAX exactly (regression test).
                          • Double columns round-trip high-precision values exactly (regression test).
                          • Hydration reads typed columns directly rather than via std::wstring.
                          Related (tracked separately)
                          Consolidates #15 (int truncation) and #16 (REAL precision), which were symptoms of this single root cause and are closed as duplicates of this issue.
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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

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                              Hydration round-trips every fetched value through std::wstring (lossy + slow reads) #17
                              Closed
                              #31
                              Closed
                              Hydration round-trips every fetched value through std::wstring (lossy + slow reads)#17
                              #31
                              Labels
                              bugSomething isn't workingenhancementNew feature or requestperformance
                              Description
                              @jkalias
                              jkalias
                              opened on Jun 15, 2026
                              Problem
                              Database::Fetch builds a FetchQueryResults whose row_values is a std::vector<std::vector<std::wstring>> (include/fetch_query_results.h). FetchRecordsQuery::GetResults stringifies every column into a wstring via GetColumnValue, and FetchRecordsQuery::Hydrate then parses each string back into the typed member. This text round-trip on the read path is both a performance cost and the root cause of two concrete data-corruption bugs.
                              Concrete defects caused by the text round-trip
                              1. 64-bit integers truncated to 32 bits (consolidated from #15)
                              GetColumnValue reads SQLITE_INTEGER with the 32-bit sqlite3_column_int (return std::to_wstring(sqlite3_column_int(stmt_, col));), and FetchMaxIdQuery::GetMaxId does the same. Any stored int64_t above INT32_MAX — including AUTOINCREMENT ids once they grow large — is silently truncated/wrapped on read, breaking subsequent Fetch(id) / Update / Delete. Fix: use sqlite3_column_int64.
                              2. REAL values lose precision (consolidated from #16)
                              GetColumnValue formats SQLITE_FLOAT via std::to_wstring(double), which uses %f with a fixed 6 decimal places, so e.g. 0.123456789 round-trips back as 0.123457 and large/scientific magnitudes are mangled. Writes are fine (sqlite3_bind_double stores the true value); the loss is only on the read path. Fix: read sqlite3_column_double directly, or format with full round-trip precision (%.17g).
                              Performance / memory
                              • Every value incurs an allocation + parse on top of the SQLite copy; significant for wide rows / large result sets.
                              • The entire result set is materialized as strings before hydration (no streaming), so large queries hold the whole set twice (string + typed form).
                              Suggested direction
                              Hydrate directly from the prepared statement using the typed column accessors (sqlite3_column_int64, sqlite3_column_double, sqlite3_column_text/_bytes) into the destination members, skipping the intermediate wstring. This removes the per-value allocation/parse, fixes both data-corruption bugs above at the source, and opens the door to row-by-row streaming.
                              Acceptance criteria
                              • Integer columns round-trip values greater than INT32_MAX exactly (regression test).
                              • Double columns round-trip high-precision values exactly (regression test).
                              • Hydration reads typed columns directly rather than via std::wstring.
                              Related (tracked separately)
                              Consolidates #15 (int truncation) and #16 (REAL precision), which were symptoms of this single root cause and are closed as duplicates of this issue.
                              Metadata
                              Metadata
                              Assignees
                              No one assigned
                                Labels
                                bugSomething isn't workingenhancementNew feature or requestperformance
                                Projects
                                No projects
                                  Milestone
                                  No milestone
                                  Relationships
                                  None yet
                                  Development
                                  No branches or pull requests
                                  Issue actions